The god fathers of gemstone inclusions shares their passion + the inner gemscapes of colored stones in colorful language (s).
Edward Gubelin / John Koivula writes:
The world of human conception is predominantly one of vision, and thus a world of light, color and form—all three phenomenological expressions of inclusions in gemstones. Their liveliness, their transitory play of light, meets not merely with the commonsense of beauty; they are even a functional necessity to human beings. Color is the most beautiful manifestation of light; the ornamentation of one of the most perceptible displays of the material world, through both one experiences a beguiling feast for the eyes when admiring inclusions.
Light is nowadays only rarely the photosphere which, bordered by darkness, verifies itself with even more intensive radiation. Everything around us is so illuminated—with the touch of a switch all becomes shadowlessly bright—that for sheer brightness we are no longer susceptible to light. Not so the illumination of inclusions in gemstones. Here a light goes on, and one experiences ethereal hours of sublime perception, amazement and interminable fascination.
Herein lie the glorious colors of contrasts, the rich light of internal reflections, the deeply impressive designs of patterns—massed apparitions of beauty—arrayed enlarged before us beneath the microscope, and one feels transported to another world of light. Whatsover quickens the human heart; the colors of flowers, the glistening plumage of the Hummingbird, the shimmering velvet of the butterfly’s wing, the sparkle of the morning dew, the radiating expressions of a beloved eye—all find their equivalence in gemstone inclusions; for these lend their unvarying, stately character to their costly encasement. Certainly they are flowers without scent, waters without eddies, gardens without movement or change, butterflies without life—shimmering treasures of an established, petrified, mystical world. And yet not an inhuman world; for it must be considered that human beings are necessary to treasure and admire.
The artistic arrangements within gemstones are, thanks to their well-balanced elegance, not only indestructible fountains of amazement and delight, but, in their multiplicity, witnesses to the creative versatility of nature. Her innovations are inexhaustible and fantastic. Finding a satisfactory solution to a certain problem, she rest not with self-satisfaction, simply spreading her invention worldwide. Instead she seems intent on demonstrating that this same problem can be solved just as excellently in many other ways with charm and artistic perfection. The outer shells, which nature has developed to protect her various creations, are astonishingly well-suited to the external conditions. Supple fish have their scales, birds their feathers, soft creatures their shells, wild animals their pelts, and inclusions—the eloquent witnesses of terrestrial history—their inert, imperishable showcase—the costly gemstone.
We gemologists have often been accused of spiriting away the nimbus of gemstones with our instruments. This criticism is unjustified, for we have opened up a magic world to the professional and layman which they could never have entered without gemological microscopy.
Sunday, July 01, 2007
EXCLUSIVE: From Today Luxury Brand Retailer Montblanc Commits To Disclose Color Enhancement Treatments Of Its Black Diamonds
Chaim Even-Zohar writes about the disclosure practices of luxury brands such as Montblanc + FTC guides for the jewelry, precious metals, and pewter industries + Diamond Best Practice Principles + the Richemont Connection + other viewpoints @ http://www.idexonline.com/portal_FullEditorial.asp?TextSearch=&KeyMatch=0&id=26465
Jewellery Exports To US Lose GSP Crutch
Times News Network writes:
Despite strong lobbying by the Indian industry for extension of duty-free access to Indian gold jewellery in the US market, the US government withdrew the generalised system of preferences (GSP) benefit for the product on Thursday.
Other products for which import duty concession was withdrawn as part of the annual review of the GSP scheme include brass lamps from India, gold jewellery from Thailand and auto-parts from Brazil. The GSP scheme provides preferential duty-free entry into the US market to select products from developing countries.
Though widely anticipated, the withdrawal of the benefits has come as a double whammy for jewellery and brass lamp exporters from India who are battling an appreciating rupee that is leading to lower realisation. Jewellery exporters will now have to pay an import duty of 6.7% which will push up prices and lower the competitiveness of the industry in the US market.
US trade representative Susan Schwab had warned the Indian industry during her India visit in April this year that they should not expect an extension of the GSP benefit for gold jewellery when the scheme lapsed in June. She pointed out that as jewellery exports from India in 2006 had crossed $2 billion, it did not qualify for the benefit any more under the revamped qualification criteria of 2006.
The new rules allow the administration to revoke waivers when imports of a product from one country exceeds an annual cap of about $ 1.87 billion or comprises 75% of total US imports of that product. The GSP scheme was introduced by the US government in January 1976 for more than 4,650 products from about 140 countries including India. In 1992, the US had suspended GSP benefits for a large number of products exported by India apparently to express its unhappiness over the intellectual property rights regime in India. In August 2001, GSP benefits on 42 products from India were restored.
The US has also withdrawn GSP benefits on wiring harnesses from the Philippines, and methanol from Venezuela. The India lobby in the US Parliament had tried hard to get the GSP benefit extended for Indian jewellery exporters. In a letter to US trade representative Susan Schwab, two senior parliamentarians had argued that revoking the benefit scheme for gems & jewellery from India and Thailand was not justified as it would only help China in grabbing a larger share of the market.
More info @ http://economictimes.indiatimes.com/Jewellery_exports_to_US_lose_GSP_crutch/articleshow/2162769.cms
Despite strong lobbying by the Indian industry for extension of duty-free access to Indian gold jewellery in the US market, the US government withdrew the generalised system of preferences (GSP) benefit for the product on Thursday.
Other products for which import duty concession was withdrawn as part of the annual review of the GSP scheme include brass lamps from India, gold jewellery from Thailand and auto-parts from Brazil. The GSP scheme provides preferential duty-free entry into the US market to select products from developing countries.
Though widely anticipated, the withdrawal of the benefits has come as a double whammy for jewellery and brass lamp exporters from India who are battling an appreciating rupee that is leading to lower realisation. Jewellery exporters will now have to pay an import duty of 6.7% which will push up prices and lower the competitiveness of the industry in the US market.
US trade representative Susan Schwab had warned the Indian industry during her India visit in April this year that they should not expect an extension of the GSP benefit for gold jewellery when the scheme lapsed in June. She pointed out that as jewellery exports from India in 2006 had crossed $2 billion, it did not qualify for the benefit any more under the revamped qualification criteria of 2006.
The new rules allow the administration to revoke waivers when imports of a product from one country exceeds an annual cap of about $ 1.87 billion or comprises 75% of total US imports of that product. The GSP scheme was introduced by the US government in January 1976 for more than 4,650 products from about 140 countries including India. In 1992, the US had suspended GSP benefits for a large number of products exported by India apparently to express its unhappiness over the intellectual property rights regime in India. In August 2001, GSP benefits on 42 products from India were restored.
The US has also withdrawn GSP benefits on wiring harnesses from the Philippines, and methanol from Venezuela. The India lobby in the US Parliament had tried hard to get the GSP benefit extended for Indian jewellery exporters. In a letter to US trade representative Susan Schwab, two senior parliamentarians had argued that revoking the benefit scheme for gems & jewellery from India and Thailand was not justified as it would only help China in grabbing a larger share of the market.
More info @ http://economictimes.indiatimes.com/Jewellery_exports_to_US_lose_GSP_crutch/articleshow/2162769.cms
Arranging A Collection
2007: Gordon Axon's tips on arranging gem collection is superb and practical. Once when you start doing it, you enjoy it because now you see what the gemstones look like when they are in its right place.
(via The Journal of Gemmology, Vol.13, No.1, January 1972) Gordon V Axon writes:
A collector faces immediately the problem of arranging his collection. In the United States, where the author currently lives, mineral and gem collecting is probably more advanced than anywhere else in the world, and the mechanical ability of Americans has been applied to the problems facing collectors. As a result, several companies provide a range of cases, cartons, trays, cabinets, stands, and gem holders.
Even so, collectors sometimes still need custom-made boxes, so even in the United States problems are still faced by collectors. One trouble lies in the variety of acquisitions, since gems come from minerals, and minerals come in all shapes and sizes, on matrix, as separate crystals, and as rough.
A display cabinet of the type known in Europe is no doubt the best way to exhibit fine mineral specimens for daily pleasure. Special supports may be needed for large specimens, but, otherwise, the plastic supports commonly available should suffice for medium-sized specimens, while the varieties of plastic-rubber will support separate crystals. Good sparkling lighting is essential, with ultra-violet for fluorescent specimens.
Gem collectors are a breed apart, since they usually deal with much smaller items that convey a different type of pleasure and indulge distinct intellectual tastes. Specifically, gem collectors are often concerned with fairly small stones, or with stones that have unusual characteristics.
In both cases, the visual pleasure affordable by a modest collection along these lines need not necessarily be great enough to compel an open collection that can be viewed readily. It may suffice to use stone papers arranged in any way suitable for the user. Should the visual pleasure be a factor, several facilities are available that combine in varying degree the visual pleasure with ease of access.
A wooden board could be drilled for cavities for the stones that would be protected by a sliding glass top. The trouble here is that the stones would move around and often present less than their must attractive view. Pads of cotton (cotton wool) or plastic foam would help.
Yet small plastic boxes that hold a single gem might prove better since they are easily stored in a cardboard box. These small plastic boxes, readily available in the United States, are hinged clear-plastic boxes often with hard-foam lining, and a soft-foam within the lid. The gem is displayed simply by opening the hinged top. Here, of course, there is no simple visual inspection since all the hinged boxes would have to be opened each time a collection was displayed, but for valuable single gems the idea is worth considering. In a sense, each gem is treated as a ring in a box.
As a rule, foam is superior to cotton wool (known as cotton in the United States) or any other lint-producing substance, since foam provides varying degrees of support, according to type used, and does not produce the irritating strands and wisps of cotton wool. Several stones can easily be accommodated in the larger plastic boxes complete with foam linings for base and cover. Depressions are easily made in this substance and the stones arranged as needed. These larger boxes are suitable for several stones of the same mineral variety, or of several varieties, or of the same cut, or of several cuts. Large gems, crystal or rough and cut to match, can also be accommodated.
Glue, of course, should not be used to fix the stones. There is no need, quite apart from spoiling the stone and the viewing. Sometimes, gem mounting prongs are useful. These may be home-made or bought. They are suitable for most stones of any reasonable size and consist of flexible plastic or metal strands or fibres attached to a central support that can be pushed into hard foam for display.
Yet all these types of covered boxes suffer from the lack of easy viewing. There’s nothing like being able to take a look at a collection without all the bother of opening stone papers or folding back plastic hinges. One method suitable for gem collectors is the custom-made box of wood, with hinged lid, containing two trays each divided into say 50 small compartments. Each tray base and the inside of the lid are well padded to protect the stones and keep them in place. A simple opening of the box would disclose 50 stones, for instance, while the lifting of the top tray would reveal the other 50—in short, 100 gems on display almost immediately.
A method very suitable for cabochons is the wooden tray lined with foam and covered with glass that can be simply lifted by a tag and removed. These come in many sizes, ranging for instance from four inches by six, to twelve inches by sixteen. The wood, in this particular advertisement, is either pine or mahogany. The foam is blue or white.
Other firms have similar boxes, ranging up to one inch or more deep, that are filled with cotton wool, padding, or plastic foam. Such boxes, especially the smaller ones, can be very suitable for faceted gems even though the glass exerts some pressure on the stones. This does not matter very much, of course, with cabochons, but faceted gems are another thing entirely. Even so, these trays are very useful for most gems. Those trays with glass tops have the problem of removing the glass when stones are being changed, but that is easily done. The shallow cardboard boxes with glass top in cover have the problem of removing the side pins and taking off the cover. Here again, the problem is minor although the replacing of the tight cover may upset the arranged stones. The pins simply go through the cardboard sides and keep the cover in place. The boxes range from small to large.
These are just some of the many, often ingenious, ways of displaying collections. Of interest to collectors of small mineral specimens are the display cases with rising levels complete with plastic cassettes, or holders, of the small specimens. The result is a minor football stadium, each individual seat being a mineral specimen. Special cases are also available for thumbnail specimens and micromounts as well as the miniatures.
In short, in the United States, at least, there is a galaxy of choice. There’s no doubt that a fine and easy way of displaying adds considerable enjoyment to a collector’s pleasure.
(via The Journal of Gemmology, Vol.13, No.1, January 1972) Gordon V Axon writes:
A collector faces immediately the problem of arranging his collection. In the United States, where the author currently lives, mineral and gem collecting is probably more advanced than anywhere else in the world, and the mechanical ability of Americans has been applied to the problems facing collectors. As a result, several companies provide a range of cases, cartons, trays, cabinets, stands, and gem holders.
Even so, collectors sometimes still need custom-made boxes, so even in the United States problems are still faced by collectors. One trouble lies in the variety of acquisitions, since gems come from minerals, and minerals come in all shapes and sizes, on matrix, as separate crystals, and as rough.
A display cabinet of the type known in Europe is no doubt the best way to exhibit fine mineral specimens for daily pleasure. Special supports may be needed for large specimens, but, otherwise, the plastic supports commonly available should suffice for medium-sized specimens, while the varieties of plastic-rubber will support separate crystals. Good sparkling lighting is essential, with ultra-violet for fluorescent specimens.
Gem collectors are a breed apart, since they usually deal with much smaller items that convey a different type of pleasure and indulge distinct intellectual tastes. Specifically, gem collectors are often concerned with fairly small stones, or with stones that have unusual characteristics.
In both cases, the visual pleasure affordable by a modest collection along these lines need not necessarily be great enough to compel an open collection that can be viewed readily. It may suffice to use stone papers arranged in any way suitable for the user. Should the visual pleasure be a factor, several facilities are available that combine in varying degree the visual pleasure with ease of access.
A wooden board could be drilled for cavities for the stones that would be protected by a sliding glass top. The trouble here is that the stones would move around and often present less than their must attractive view. Pads of cotton (cotton wool) or plastic foam would help.
Yet small plastic boxes that hold a single gem might prove better since they are easily stored in a cardboard box. These small plastic boxes, readily available in the United States, are hinged clear-plastic boxes often with hard-foam lining, and a soft-foam within the lid. The gem is displayed simply by opening the hinged top. Here, of course, there is no simple visual inspection since all the hinged boxes would have to be opened each time a collection was displayed, but for valuable single gems the idea is worth considering. In a sense, each gem is treated as a ring in a box.
As a rule, foam is superior to cotton wool (known as cotton in the United States) or any other lint-producing substance, since foam provides varying degrees of support, according to type used, and does not produce the irritating strands and wisps of cotton wool. Several stones can easily be accommodated in the larger plastic boxes complete with foam linings for base and cover. Depressions are easily made in this substance and the stones arranged as needed. These larger boxes are suitable for several stones of the same mineral variety, or of several varieties, or of the same cut, or of several cuts. Large gems, crystal or rough and cut to match, can also be accommodated.
Glue, of course, should not be used to fix the stones. There is no need, quite apart from spoiling the stone and the viewing. Sometimes, gem mounting prongs are useful. These may be home-made or bought. They are suitable for most stones of any reasonable size and consist of flexible plastic or metal strands or fibres attached to a central support that can be pushed into hard foam for display.
Yet all these types of covered boxes suffer from the lack of easy viewing. There’s nothing like being able to take a look at a collection without all the bother of opening stone papers or folding back plastic hinges. One method suitable for gem collectors is the custom-made box of wood, with hinged lid, containing two trays each divided into say 50 small compartments. Each tray base and the inside of the lid are well padded to protect the stones and keep them in place. A simple opening of the box would disclose 50 stones, for instance, while the lifting of the top tray would reveal the other 50—in short, 100 gems on display almost immediately.
A method very suitable for cabochons is the wooden tray lined with foam and covered with glass that can be simply lifted by a tag and removed. These come in many sizes, ranging for instance from four inches by six, to twelve inches by sixteen. The wood, in this particular advertisement, is either pine or mahogany. The foam is blue or white.
Other firms have similar boxes, ranging up to one inch or more deep, that are filled with cotton wool, padding, or plastic foam. Such boxes, especially the smaller ones, can be very suitable for faceted gems even though the glass exerts some pressure on the stones. This does not matter very much, of course, with cabochons, but faceted gems are another thing entirely. Even so, these trays are very useful for most gems. Those trays with glass tops have the problem of removing the glass when stones are being changed, but that is easily done. The shallow cardboard boxes with glass top in cover have the problem of removing the side pins and taking off the cover. Here again, the problem is minor although the replacing of the tight cover may upset the arranged stones. The pins simply go through the cardboard sides and keep the cover in place. The boxes range from small to large.
These are just some of the many, often ingenious, ways of displaying collections. Of interest to collectors of small mineral specimens are the display cases with rising levels complete with plastic cassettes, or holders, of the small specimens. The result is a minor football stadium, each individual seat being a mineral specimen. Special cases are also available for thumbnail specimens and micromounts as well as the miniatures.
In short, in the United States, at least, there is a galaxy of choice. There’s no doubt that a fine and easy way of displaying adds considerable enjoyment to a collector’s pleasure.
If There’s A Doubt Have It Tested
2007: A E Farn's tips on gem testing is still valid today, but diamond simulants such as synthetic cubic zirconia and synthetic moissanite are the most frequently encountered stones in the gem market. In my view, today synthetic cubic zirconia is still the best + affordable diamond simulant. There are new synthetics such synthetic amethyst, citrine, ametrine + synthetic ruby, sapphires (flame fusion/flux/hydrothermal), synthetic emerald + colored varieties (hydrothermal/flux), synthetic diamond (HPHT/CVD) + treated colored stones that are giving new headaches for the practising gemologist.
(via Journal of Gemmology, Vol.IX, No.10, April, 1965) A E Farn writes:
This advertising phrase is apt and very rewarding. In the world of gem testing there were some stones which hardly needed testing, since they were impossible to copy or imitate successfully. Emeralds use to be easy—if red under a filter, it was an emerald. Black opals were once a certainty, but nowadays there are treated or carbonized opals of a very attractive appearance but which are not exactly as one would expect when a stone is termed ‘black opal’.
Possibly one of the least tested stones is the diamond. By diamond I mean transparent white diamond, not any fancy color or hue, since the detection of possible treatment is a separate and very technical problem on its own.
Diamond is the hardest known gemstone and in what one terms ‘the good old days’ an anvil was said to shattered quite readily when a diamond was tested upon it by striking. Apart from being the hardest known gemstone it also has a now well-recognized weakness, i.e. cleavage. We all know what would happen if we placed a diamond on an anvil and struck it a heavy blow.
A gem testing laboratory sees more unusual stones from hopeful jewelers than most people in this trade. Some people specialize in certain stones such as star stones and cat’s eyes, emeralds and opals, or rubies and sapphires. Diamond dealers proper seldom mix with the colored stone trade. It is interesting, sometimes, to see an obvious large synthetic ruby brought in by a dealer who usually specializes in diamonds only.
Whilst there are colored stone dealers, and diamond dealers, there are dealers who dabble in many gems including corals, pearls, ivories, etc. and seldom do these people manage to specialize in any particular one.
How much more difficult then is it for the retail jeweler who has to consider all these, together with watches, clocks, gold, silver, plated wares and repairs and estimates. Small wonder then that the jeweler who is suddenly confronted with a pearl necklace, a chrysoberyl cat’s eye ring or a fine pink sapphire in a cluster surround sometimes feels himself at loss to identify such gems.
‘Are they diamond’ ‘or is it a diamond’ is the kind of question which brings quick reaction. But, and it is a very big but, once doubt is sown in the mind then fermentation takes place and the slogan ‘If there’s a doubt have it tested’ pays its dividend.
In the laboratory quite recently we had an old cut long cushion-shape thick diamond of good quality brought in by a slightly irate though somewhat apologetic diamond dealer. I thought he wanted it weighed to settle a point one way or the other. He said ‘I want it tested’. To me, it was so obviously a diamond. I could not help pointing this out as diplomatically as possible (after all he was a diamond dealer). To my relief he immediately agreed, ‘Yes, indeed I know it is a diamond but someone has doubted it because it is an old stone.’ Thus we had the crux of the matter—a doubt. This particular case, one of a few I can recall, was outstanding in its sharpness of doubt and certainty. Others, of course, are a good deal more nebulous.
Some while ago a dealer asked me if I was interested in a parcel of rose-cut diamonds and on being shown them I suggested he had them tested. He protested that they were all old Indian stones but to me they looked like zircon—and a check by spectroscope confirmed the diagnosis.
Another dealer had a diamond and onyx eternity ring, which had been fished up from the sewers by a sewerman, and the diamonds were very rubbed indeed—no one could have said what the stones were by just looking.
It is my experience that pawnbrokers above all seem to be considered fair game to the unscrupulous. Most pawnbrokers are open not only to lend money on valuables but are very often more liable to buy jewelry from the public than many retail jewelers. Therefore more people ‘try it on’ with pawnbrokers than otherwise. I am, perhaps, specifying the pawnbroker at the moment because the average retail jeweler buys from regular suppliers mostly new goods. These in turn are obtained from manufacturers who are buying their diamonds direct from well-known sources of supply. It is not these kinds of goods I have in mind.
Quite frequently a very pleasing ring (with, say, a circular amethyst or golden quartz) is mounted in a cast setting with a cluster surround of synthetic white spinels. Very clean and newly polished it looks very pleasant because the cast is from a very good patten and perhaps the finish of the ring by the polisher has been well done. This kind of ring after being worn a little (with a little dust, or powder or soap accumulation behind it) if offered over the counter under artificial light at a reasonable asking price, can cause an error. When goods are offered too cheaply suspicion is aroused. If offered at a reasonable price—then commerce overcomes gemology (if there is any gemology).
Sometimes it happens a diamond is cut with too much spread to make it look more for the money and the stone looks a little ‘laxey’, a term somewhat similar to ‘lasque’, which is used to describe a very thin flat style of cutting from India. When a diamond is cut in a manner which is not familiar to the jeweler then he is troubled. A very tricky point arises sometimes when a stone is baguette-shape and used a shoulder stone to a ring, and is set flush with the metal. This allows very little chance of inspection, due to the mount immediately obtruding when by turning the ring the stone is examined.
Artificial lighting can mislead when quickly looking at a cluster-set ring, especially if one has approached the problem by examining the center stone and assuming a diamond cluster surround. Lack of ‘fire’ can thus be put down to general dirtiness at the back and a mental note that it will improve if the ring is cleaned. It is usually the next day, with daylight to help and a clean-up of the accumulated debris from behind the stones, that the truth becomes apparent.
By these observations it is not intended or suggested that jewelers and pawnbrokers are constantly being taken in by unscrupulous methods, because the majority make their living adequately enough to disprove any such opinion.
With the advent of strontium titanate, however, I think it to be a little dangerous to assume too readily that diamonds never need testing. One afternoon, about 2 years ago, I had a strontium titanate single stone ring in to test from a West End jeweler. Immediately following we had a cluster ring from the National Association of Goldsmiths to test for one of their members. The center stone was a strontium titanate with a cluster surround of reasonably good quality diamonds. The whole effect was good and if a little dirtier could have passed as a very fine all-diamond cluster. Two rings in immediate succession one afternoon having strontium titanates in them was remarkable.
‘Diamonds are forever,’ as a title, indicates the inherent hardness and durability of diamonds. This hardness of diamond is its important factor—it is related to the quality of polish the stone can take, and upon the finish of the facet edges. In fact, a hard look and finish. Because of its simple chemical and molecular structure diamond has a single refraction and a characteristic optical clarity. Such is this impressive quality that when viewed through the table facet with a lens the culet seems to be very close to the table.
The stones which are most commonly used in jewelry in place of diamonds or as diamond simulants are: (1) synthetic spinel, (2) synthetic sapphire and natural colorless sapphire, (3) zircon, (4) synthetic rutile, (5) strontium titanate, (6) paste, with high refractive index. There may be others—one can cite almost any colorless stone, but I think the stones listed are the most commonly used and reasonable to expect.
Jewelry which is ‘diamond’—set, if suspect, should be cleaned in order that information can be obtained by visual methods. A clean stone or stones in settings are much more easy to test if light can readily be transmitted.
In a cluster setting synthetic spinels are very quickly identified by immersing in methylene iodide because their refractive indices very nearly match at 1.728 and 1.74 respectively. The effect can be quite startling, the stones tend to disappear from their settings an empty mount is left.
Since natural spinels do not exist as colorless stones (they always draw a little color in comparison to a parcel of diamonds or synthetic spinels), it is safe to assume the synthesis of the spinels. Synthetic sapphires, as opposed to diamond, are doubly refracting (as shown by a doubling of the back facets or the effect seen when a piece of jewelry is revolved between fixed crossed polaroids). Although it is safe to assume that all spinels which are colorless in a setting are likely to be synthetic it is not the same case with colorless sapphires.
Usually, of course, one is not trying especially to identify the suspect colorless stone—only to avoid buying it as a diamond. Natural colorless sapphires are very bright stones and it is not unusual to find them in cluster settings surrounding a genuine blue sapphire in jewelry emanating, say, from Ceylon. Examination by microscope will sometimes reveal crystalline inclusions, feathers, silk, etc. in even very small stones.
Synthetic colorless sapphires will very often show included gas bubbles much more readily than synthetic spinels. A thorough cleaning of the backs of small cluster-set jewelry is really important when examination has to be made by microscope. Being a cheap product synthetics are very seldom well cut or polished and reveal this by certain small useful factors such as fire or chatter marks on the new face. These marks are caused by heating due to pressures in polishing and are seen as slight surface cracks in a slightly zig-zag manner. They are more frequently seen on synthetic stones than on genuine ones.
Colorless zircons, because of their superior fire are a very good imitation of diamonds. With zircons, providing one is a reasonably well-versed jeweler, gemologist or probationer, it is a fairly easy matter to see quite distinct double refraction evidenced by the doubling of back facets. I have quoted jeweler, gemologist or probationer because one presumes that readers of the Journal of Gemmolgy are just that. Colorless zircons are brittle and soft and usually reveal this by the very frequent chipping and worn appearance of the facet edges. Zircons have a muzzy look when viewed through the table facet with a lens. This ‘out of focus’ appearance is due to the market double refraction.
Should very small rose-cut or brilliant-cut colorless zircons be used in cluster setting the stones may be slightly rubbed or no double refraction easily recognizable, and then the spectroscope comes into its own. The well-known absorption band seen in the red end of the spectrum at 6535 angstrom is completely diagnostic for zircon—very easy to find and practically infallible in showing (besides other lines) in zircon. The spectroscope knows no barriers of size, cut, polish, rough, or water-worn.
Synthetic rutile with its play of color should never cause any hesitation even to a non-gemologist jeweler. Its large double refraction is to startling as to make the doubling of back facets look like separate distinct facet edges. Synthetic rutile is the extrovert among stones. Rutile does not exist in nature as cuttable rough material and certainly no rough or natural rutile ever looked like a poor relation to the poorest quality in diamond used in jewelry. Synthetic rutile in any case cannot get that white or colorless aspect of diamond. It always look a little yellow or off-white.
Strontium titanate is the most dangerous to the jeweler. Although it has too much fire in its pristine state it can be dangerous when a little rubbed or dirty. Strontium titanate is very soft and has a slightly molded look if observed carefully at the facet edges with a lens. Apart from an old-fashioned (but very practical in this case) hardness test, there is little one can do to identify a strontium titanate except by examining certain abrasive marks seen under laboratory conditions. For an artificial stone it is quite expensive—the smaller sizes are more expensive per carat than the larger sizes. Its brilliance and fire cause it to stand out as superior to diamond but its soft look and rounded facet-edges betray it. Strontium titanate is much heavier than diamond and if a stone is loose this factor can be used against it. Quite recently a friend of mine ordered a strontium titanate with a 1 carat diamond spread. In actual fact it weighed 1.61 carats. So that comparison of a stone by gauge to actual scale weight can be very informative.
High refractive index pastes are sometimes deceiving. One always thinks immediately of swirl striae and bubbles, but they are not always seen. In an antique ring of backed table-cut stones it is not always wise to attempt a hardness test. It a spinel refractometer is available a refractive index reading is often possible and here information is quickly gained if the resultant reading seen on the scale of the spinel refractometer has a color fringe. These color fringe readings indicate paste as opposed to glass. Because of the high dispersion of most pastes a colored fringe or edge is seen as the reading on the refractometer scale. Pastes from 1.61 upwards especially towards 1.65, 1.66, 1.67, etc. show this effect clearly. Similarly if a paste-set article cannot be checked on a refractometer for various reasons often it will yield information if immersed in monobromonapthalene. Monobromonapthelene has a refractive index of 1.66 and pastes around this reading will tend to disappear or the facet edges fade when a stone of jewelry is immersed. In contrast, diamond will stand out clearly. Certainly it is helpful also to find swirls or bubbles, but immersion will readily distinguish paste from diamond, and it is the elimination of suspects from diamond we aim at in this article, not necessarily complete identification of the stimulant.
We have dealt with the stones most likely to be met with as diamonds and discussed their characteristics. What if the stones are diamonds? Nowadays with the decline in horse drawn traffic anvils are not so common, so the gemologist usually equips himself with a large cheap synthetic ruby or sapphire with a large table to it. Diamond will scratch synthetic ruby or sapphire. Brute strength is not required. Diamonds have a clarity and brilliance unapproached by any other stone. Very often the girdle of a diamond has a small natural unpolished facet left on it, either by design or fortuitously, and this is very helpful. Although this is not a laboratory test, I have frequently noticed how even a light touch of the finger on the table facet of a diamond leaves an imprint of grease from the skin (or fingerprint) very sharply defined indeed bearing ample witness to the well-known affinity diamond has for grease. Diamonds will stand out sharply in methylene iodide. Diamond facet-edges have a quality of finish and a degree of hardness not seen in any other stone. Simple tests to prove diamond are the hardness test against synthetic corundum and high relief in methylene iodide. Laboratory refinements, of course, are infinite, and include fluorescence, under X-ray excitation or long and short wave lamps. Electro-conductivity tests also play their part, but by and large it is: Look first, lens second, opinion third and then proof by whatever methods seems obvious, expedient and positive. The X-ray excitation or short wave lamps, etc. are refinements but all add to and play very useful part in this identification of diamond, this common stone that seldom needs testing—or does it?
A reiteration of factors in the foregoing to eliminate diamond simulants from diamond may be helpful here. Synthetic spinels are single refracting, disappear in methylene iodide, and are scratched by sapphire and diamond. Synthetic sapphires are double refractive, often have bubbles and chatter marks, and are scratched by diamond. Zircons are soft, brittle, strongly doubly refracting, have a 6536 angstrom line and are heavy stones. Synthetic rutile has tremendous double refraction, strong play of color, and is markedly off-white. Strontium titanate—tremendous fire, singly refracting, soft facet edges and girdle, ‘centipede’ outline scratch marks. High R.I pastes—sometimes bubble and swirl marks, are very soft and disappear in monobromonapthelene; heavy, color fringe on spinel refractometer; single refraction.
Diamond is single refracting and has an affinity for grease. It will easily scratch all other gemstones including sapphire and ruby (both natural and synthetic). Sharp relief is shown in methylene iodide. It has optical clarity, extreme hardness and polish, and sharp facet edges. Diamond fluoresces milky-blue when excited by X-rays. It has characteristic carbon inclusions and may show naturals on the girdle.
(via Journal of Gemmology, Vol.IX, No.10, April, 1965) A E Farn writes:
This advertising phrase is apt and very rewarding. In the world of gem testing there were some stones which hardly needed testing, since they were impossible to copy or imitate successfully. Emeralds use to be easy—if red under a filter, it was an emerald. Black opals were once a certainty, but nowadays there are treated or carbonized opals of a very attractive appearance but which are not exactly as one would expect when a stone is termed ‘black opal’.
Possibly one of the least tested stones is the diamond. By diamond I mean transparent white diamond, not any fancy color or hue, since the detection of possible treatment is a separate and very technical problem on its own.
Diamond is the hardest known gemstone and in what one terms ‘the good old days’ an anvil was said to shattered quite readily when a diamond was tested upon it by striking. Apart from being the hardest known gemstone it also has a now well-recognized weakness, i.e. cleavage. We all know what would happen if we placed a diamond on an anvil and struck it a heavy blow.
A gem testing laboratory sees more unusual stones from hopeful jewelers than most people in this trade. Some people specialize in certain stones such as star stones and cat’s eyes, emeralds and opals, or rubies and sapphires. Diamond dealers proper seldom mix with the colored stone trade. It is interesting, sometimes, to see an obvious large synthetic ruby brought in by a dealer who usually specializes in diamonds only.
Whilst there are colored stone dealers, and diamond dealers, there are dealers who dabble in many gems including corals, pearls, ivories, etc. and seldom do these people manage to specialize in any particular one.
How much more difficult then is it for the retail jeweler who has to consider all these, together with watches, clocks, gold, silver, plated wares and repairs and estimates. Small wonder then that the jeweler who is suddenly confronted with a pearl necklace, a chrysoberyl cat’s eye ring or a fine pink sapphire in a cluster surround sometimes feels himself at loss to identify such gems.
‘Are they diamond’ ‘or is it a diamond’ is the kind of question which brings quick reaction. But, and it is a very big but, once doubt is sown in the mind then fermentation takes place and the slogan ‘If there’s a doubt have it tested’ pays its dividend.
In the laboratory quite recently we had an old cut long cushion-shape thick diamond of good quality brought in by a slightly irate though somewhat apologetic diamond dealer. I thought he wanted it weighed to settle a point one way or the other. He said ‘I want it tested’. To me, it was so obviously a diamond. I could not help pointing this out as diplomatically as possible (after all he was a diamond dealer). To my relief he immediately agreed, ‘Yes, indeed I know it is a diamond but someone has doubted it because it is an old stone.’ Thus we had the crux of the matter—a doubt. This particular case, one of a few I can recall, was outstanding in its sharpness of doubt and certainty. Others, of course, are a good deal more nebulous.
Some while ago a dealer asked me if I was interested in a parcel of rose-cut diamonds and on being shown them I suggested he had them tested. He protested that they were all old Indian stones but to me they looked like zircon—and a check by spectroscope confirmed the diagnosis.
Another dealer had a diamond and onyx eternity ring, which had been fished up from the sewers by a sewerman, and the diamonds were very rubbed indeed—no one could have said what the stones were by just looking.
It is my experience that pawnbrokers above all seem to be considered fair game to the unscrupulous. Most pawnbrokers are open not only to lend money on valuables but are very often more liable to buy jewelry from the public than many retail jewelers. Therefore more people ‘try it on’ with pawnbrokers than otherwise. I am, perhaps, specifying the pawnbroker at the moment because the average retail jeweler buys from regular suppliers mostly new goods. These in turn are obtained from manufacturers who are buying their diamonds direct from well-known sources of supply. It is not these kinds of goods I have in mind.
Quite frequently a very pleasing ring (with, say, a circular amethyst or golden quartz) is mounted in a cast setting with a cluster surround of synthetic white spinels. Very clean and newly polished it looks very pleasant because the cast is from a very good patten and perhaps the finish of the ring by the polisher has been well done. This kind of ring after being worn a little (with a little dust, or powder or soap accumulation behind it) if offered over the counter under artificial light at a reasonable asking price, can cause an error. When goods are offered too cheaply suspicion is aroused. If offered at a reasonable price—then commerce overcomes gemology (if there is any gemology).
Sometimes it happens a diamond is cut with too much spread to make it look more for the money and the stone looks a little ‘laxey’, a term somewhat similar to ‘lasque’, which is used to describe a very thin flat style of cutting from India. When a diamond is cut in a manner which is not familiar to the jeweler then he is troubled. A very tricky point arises sometimes when a stone is baguette-shape and used a shoulder stone to a ring, and is set flush with the metal. This allows very little chance of inspection, due to the mount immediately obtruding when by turning the ring the stone is examined.
Artificial lighting can mislead when quickly looking at a cluster-set ring, especially if one has approached the problem by examining the center stone and assuming a diamond cluster surround. Lack of ‘fire’ can thus be put down to general dirtiness at the back and a mental note that it will improve if the ring is cleaned. It is usually the next day, with daylight to help and a clean-up of the accumulated debris from behind the stones, that the truth becomes apparent.
By these observations it is not intended or suggested that jewelers and pawnbrokers are constantly being taken in by unscrupulous methods, because the majority make their living adequately enough to disprove any such opinion.
With the advent of strontium titanate, however, I think it to be a little dangerous to assume too readily that diamonds never need testing. One afternoon, about 2 years ago, I had a strontium titanate single stone ring in to test from a West End jeweler. Immediately following we had a cluster ring from the National Association of Goldsmiths to test for one of their members. The center stone was a strontium titanate with a cluster surround of reasonably good quality diamonds. The whole effect was good and if a little dirtier could have passed as a very fine all-diamond cluster. Two rings in immediate succession one afternoon having strontium titanates in them was remarkable.
‘Diamonds are forever,’ as a title, indicates the inherent hardness and durability of diamonds. This hardness of diamond is its important factor—it is related to the quality of polish the stone can take, and upon the finish of the facet edges. In fact, a hard look and finish. Because of its simple chemical and molecular structure diamond has a single refraction and a characteristic optical clarity. Such is this impressive quality that when viewed through the table facet with a lens the culet seems to be very close to the table.
The stones which are most commonly used in jewelry in place of diamonds or as diamond simulants are: (1) synthetic spinel, (2) synthetic sapphire and natural colorless sapphire, (3) zircon, (4) synthetic rutile, (5) strontium titanate, (6) paste, with high refractive index. There may be others—one can cite almost any colorless stone, but I think the stones listed are the most commonly used and reasonable to expect.
Jewelry which is ‘diamond’—set, if suspect, should be cleaned in order that information can be obtained by visual methods. A clean stone or stones in settings are much more easy to test if light can readily be transmitted.
In a cluster setting synthetic spinels are very quickly identified by immersing in methylene iodide because their refractive indices very nearly match at 1.728 and 1.74 respectively. The effect can be quite startling, the stones tend to disappear from their settings an empty mount is left.
Since natural spinels do not exist as colorless stones (they always draw a little color in comparison to a parcel of diamonds or synthetic spinels), it is safe to assume the synthesis of the spinels. Synthetic sapphires, as opposed to diamond, are doubly refracting (as shown by a doubling of the back facets or the effect seen when a piece of jewelry is revolved between fixed crossed polaroids). Although it is safe to assume that all spinels which are colorless in a setting are likely to be synthetic it is not the same case with colorless sapphires.
Usually, of course, one is not trying especially to identify the suspect colorless stone—only to avoid buying it as a diamond. Natural colorless sapphires are very bright stones and it is not unusual to find them in cluster settings surrounding a genuine blue sapphire in jewelry emanating, say, from Ceylon. Examination by microscope will sometimes reveal crystalline inclusions, feathers, silk, etc. in even very small stones.
Synthetic colorless sapphires will very often show included gas bubbles much more readily than synthetic spinels. A thorough cleaning of the backs of small cluster-set jewelry is really important when examination has to be made by microscope. Being a cheap product synthetics are very seldom well cut or polished and reveal this by certain small useful factors such as fire or chatter marks on the new face. These marks are caused by heating due to pressures in polishing and are seen as slight surface cracks in a slightly zig-zag manner. They are more frequently seen on synthetic stones than on genuine ones.
Colorless zircons, because of their superior fire are a very good imitation of diamonds. With zircons, providing one is a reasonably well-versed jeweler, gemologist or probationer, it is a fairly easy matter to see quite distinct double refraction evidenced by the doubling of back facets. I have quoted jeweler, gemologist or probationer because one presumes that readers of the Journal of Gemmolgy are just that. Colorless zircons are brittle and soft and usually reveal this by the very frequent chipping and worn appearance of the facet edges. Zircons have a muzzy look when viewed through the table facet with a lens. This ‘out of focus’ appearance is due to the market double refraction.
Should very small rose-cut or brilliant-cut colorless zircons be used in cluster setting the stones may be slightly rubbed or no double refraction easily recognizable, and then the spectroscope comes into its own. The well-known absorption band seen in the red end of the spectrum at 6535 angstrom is completely diagnostic for zircon—very easy to find and practically infallible in showing (besides other lines) in zircon. The spectroscope knows no barriers of size, cut, polish, rough, or water-worn.
Synthetic rutile with its play of color should never cause any hesitation even to a non-gemologist jeweler. Its large double refraction is to startling as to make the doubling of back facets look like separate distinct facet edges. Synthetic rutile is the extrovert among stones. Rutile does not exist in nature as cuttable rough material and certainly no rough or natural rutile ever looked like a poor relation to the poorest quality in diamond used in jewelry. Synthetic rutile in any case cannot get that white or colorless aspect of diamond. It always look a little yellow or off-white.
Strontium titanate is the most dangerous to the jeweler. Although it has too much fire in its pristine state it can be dangerous when a little rubbed or dirty. Strontium titanate is very soft and has a slightly molded look if observed carefully at the facet edges with a lens. Apart from an old-fashioned (but very practical in this case) hardness test, there is little one can do to identify a strontium titanate except by examining certain abrasive marks seen under laboratory conditions. For an artificial stone it is quite expensive—the smaller sizes are more expensive per carat than the larger sizes. Its brilliance and fire cause it to stand out as superior to diamond but its soft look and rounded facet-edges betray it. Strontium titanate is much heavier than diamond and if a stone is loose this factor can be used against it. Quite recently a friend of mine ordered a strontium titanate with a 1 carat diamond spread. In actual fact it weighed 1.61 carats. So that comparison of a stone by gauge to actual scale weight can be very informative.
High refractive index pastes are sometimes deceiving. One always thinks immediately of swirl striae and bubbles, but they are not always seen. In an antique ring of backed table-cut stones it is not always wise to attempt a hardness test. It a spinel refractometer is available a refractive index reading is often possible and here information is quickly gained if the resultant reading seen on the scale of the spinel refractometer has a color fringe. These color fringe readings indicate paste as opposed to glass. Because of the high dispersion of most pastes a colored fringe or edge is seen as the reading on the refractometer scale. Pastes from 1.61 upwards especially towards 1.65, 1.66, 1.67, etc. show this effect clearly. Similarly if a paste-set article cannot be checked on a refractometer for various reasons often it will yield information if immersed in monobromonapthalene. Monobromonapthelene has a refractive index of 1.66 and pastes around this reading will tend to disappear or the facet edges fade when a stone of jewelry is immersed. In contrast, diamond will stand out clearly. Certainly it is helpful also to find swirls or bubbles, but immersion will readily distinguish paste from diamond, and it is the elimination of suspects from diamond we aim at in this article, not necessarily complete identification of the stimulant.
We have dealt with the stones most likely to be met with as diamonds and discussed their characteristics. What if the stones are diamonds? Nowadays with the decline in horse drawn traffic anvils are not so common, so the gemologist usually equips himself with a large cheap synthetic ruby or sapphire with a large table to it. Diamond will scratch synthetic ruby or sapphire. Brute strength is not required. Diamonds have a clarity and brilliance unapproached by any other stone. Very often the girdle of a diamond has a small natural unpolished facet left on it, either by design or fortuitously, and this is very helpful. Although this is not a laboratory test, I have frequently noticed how even a light touch of the finger on the table facet of a diamond leaves an imprint of grease from the skin (or fingerprint) very sharply defined indeed bearing ample witness to the well-known affinity diamond has for grease. Diamonds will stand out sharply in methylene iodide. Diamond facet-edges have a quality of finish and a degree of hardness not seen in any other stone. Simple tests to prove diamond are the hardness test against synthetic corundum and high relief in methylene iodide. Laboratory refinements, of course, are infinite, and include fluorescence, under X-ray excitation or long and short wave lamps. Electro-conductivity tests also play their part, but by and large it is: Look first, lens second, opinion third and then proof by whatever methods seems obvious, expedient and positive. The X-ray excitation or short wave lamps, etc. are refinements but all add to and play very useful part in this identification of diamond, this common stone that seldom needs testing—or does it?
A reiteration of factors in the foregoing to eliminate diamond simulants from diamond may be helpful here. Synthetic spinels are single refracting, disappear in methylene iodide, and are scratched by sapphire and diamond. Synthetic sapphires are double refractive, often have bubbles and chatter marks, and are scratched by diamond. Zircons are soft, brittle, strongly doubly refracting, have a 6536 angstrom line and are heavy stones. Synthetic rutile has tremendous double refraction, strong play of color, and is markedly off-white. Strontium titanate—tremendous fire, singly refracting, soft facet edges and girdle, ‘centipede’ outline scratch marks. High R.I pastes—sometimes bubble and swirl marks, are very soft and disappear in monobromonapthelene; heavy, color fringe on spinel refractometer; single refraction.
Diamond is single refracting and has an affinity for grease. It will easily scratch all other gemstones including sapphire and ruby (both natural and synthetic). Sharp relief is shown in methylene iodide. It has optical clarity, extreme hardness and polish, and sharp facet edges. Diamond fluoresces milky-blue when excited by X-rays. It has characteristic carbon inclusions and may show naturals on the girdle.
Saturday, June 30, 2007
Patton
Memorable quote (s) from the movie:
Lt. Col. Charles R. Codman (Paul Stevens): You know General, sometimes the men don't know when you're acting.
Patton (George C Scott): It's not important for them to know. It's only important for me to know.
Lt. Col. Charles R. Codman (Paul Stevens): You know General, sometimes the men don't know when you're acting.
Patton (George C Scott): It's not important for them to know. It's only important for me to know.
Limited Edition
20ltd, is a new site that carries only 20 items at a time, each made exclusively for the site and limited in their production.
The Ruby Mines In Mogok In Burma
2007: Today Mogok still look pretty much the same. In Burma, everything is slow. The way of life + the ruby intrigue + the traditions still attracts a lot of Westerners to this one-of-a-kind gem deposit in the world. Edward Gubelin describes the way of life of the Burmese in a colorful tone + he happened to be one of the lucky Westerner to visit Mogok in the 1960s and collect samples from the source for his research.
(via The Journal of Gemmology, Vol.IX,No.12, October 1965) E Gubelin writes:
The ruby mines in Burma have been known for centuries and the large mining district of Mogok above a lovely lake has always proved to be of great interest because of the wonderful rubies found there. Mogok itself is full of mysteries and whoever goes there for the first time is delighted with its beautiful streets and the soft music of the bells from the temples and pagodas. The author visited this valley for the first time three years ago, after his second stay in Ceylon, and was in no way disappointed.
The western mountainous Shan-plateau rises towards the east over the middle Irrawaddy valley; there are mountains in the north and the lake to the south. The valley of rubies is narrow and long and towards its lower end lies Mogok. It is about 700 km north of Rangoon and 150 km north-east of Mandalay, the last residential town of the Burmese kings. Only 145 km east of this town is the frontier of Burma with China. The township lies about 1500 meters above sea level and is surrounded by mountainous sometimes reaching a height of 2500 meters, all covered with thick jungle. The climate is agreeable, although there is a great difference of temperature between the very hot hours around noon and the cold nights. It rains often and rainfall during the summer months of the monsoon can reach more than 250 mm. It is very rare that the temperature during the winter drops to freezing point.
At the time of writing the visa given to foreigners does not exceed 24 hours, which makes it impossible to leave Rangoon, but before this additional difficulty arose, there were several ways of going to Mogok. Mandalay can be reached by a slow train taking two days for the trip or by a four to six hour flight by the Union of Burma Airways. From Mandalay there are again several ways of reaching Mogok. One can fly on to Momeik and if one has any friends in Mogok ask them to fetch one by jeep. One then travels along a good mountainous road. But as it was well known that many robberies occurred at the time of the visit, the author thought it safer to use the official coach. The coach uses many dusty roads, full of ox-carts, along the Irrawady valley on a very bumpy road and then slowly rises on a narrow but good road through beautiful mountain country towards Mogok, where it arrives twelve hours later. Four days after the author’s safe arrival three private jeeps traveling down the valley were ambushed and robbed.
There are neither hotels nor boarding houses in Mogok, and if one wants to stay in a bungalow for government officials, one has to supply one’s own bed linen and either cook one’s meals, or eat in one of the small Chinese stalls. The author was very lucky and was invited to stay in the house of his Burmese interpreter and agent and was thus able to take part in the daily life of the family. They were all very kind and hospitable and tried to make the visit as agreeable as possible. There are only a few streets in Mogok, the most important being macadamed and at their sides are beautiful houses. Most of these are made of wood, some using teak. In the last few years a few villas were erected from stone. Around the town and in the surrounding villages the houses are made of interwoven bamboo sticks, build on piles. These airy rooms usually form the workshop and the gems are polished here. Unfortunately only the older houses are covered with straw, tiles or brick, the newer houses being covered with corrugated metal sheets, which are not attractive. Many small shops and stalls along the two main roads form the business quarter, where one can buy most consumer goods from a tea cup to a loupe or a washing basket made of bamboo strips to household articles made of plastic. Of the greatest interest is the bazaar, where there is a market every five days and the inhabitants of the surrounding districts and mountains gather in their colorful costumes to sell vegetables, herbs, baked articles, tobacco and all sorts of homemade goods and who seldom return home without looking at, or even buying a few rubies. One must also mention the waterworks and sewage arrangements, which work very well, and a very old-fashioned electricity plant which sells its electricity (220V) during the day to the mines and only after 6 pm to the townspeople, so that one can only then use the electric light. It is then used so much that the voltage falls from 220V to 110, so that one can hardly read. The foreign visitor is well advised to take a torch along together with a sufficient supply of batteries. There is no official waste disposal, so it is not surprising that there are often cases of malaria, dysentery and typhoid. The visitor must be careful in every respect. Apart from various nature-cures and quacks, there are also a few good doctors in Mogok, but hospitals, old people’s homes and orphanages are not necessary since all these services are given by the family. There is always much life in the streets. Most goods are still transported on a shoulder-yoke or by ox-cart. There are many bicycles, and a few cars and vans. The riche mine owners have land-rovers, and there are various jeeps which are used as taxis to which transport people to the surrounding villages.
Although the whole district is only a few square miles and Mogok itself only a small town, there must be about 20000 people living in the district. The inhabitants are very mixed: apart from Burmese, there are Ghurkas, Hindus, Chinese and the romantic looking people from the Schan tribe. On each side of the street, in market places, in front of the tea houses and bazaars, there are small groups of squatting women showing each other small brass bowls with rubies. One soon has the impression that the whole population from the earliest youth to the oldest age is involved in the prospecting, production and sale of rubies, whether as a mine worker, mine owner, gem merchant, polisher, host or tradesman. The people are very friendly, helpful and open: the few that speak a foreign language like to talk to visitors.
The famous ruby mines are secondary deposits, that is, they have been brought down into the valley from decomposed primary deposits. Such alluvial deposits are found in most of the smaller and larger valleys of the district, and everywhere there is prospecting for rubies. Mogok lies in the lower part of a larger valley on what used to be the most profitable deposits. When the population realized this, they moved their township to the lower part of the hills so that they could mine the rubies in the valley. When there were no rubies, the craters which were formed by the mining operations filled with water, forming the lovely Mogok Lake, which today beautifies the valley. In the neighboring valleys the yellow clay is full of holes, and looks like a volcanic field of craters.
Prospecting and mining licenses are only given to Burmese. The owner who wants to open a small mine registers his intention with the district officer, who examines the claim. Depending on the size of the mine, the owner pays several hundred Kyats (1 Kyat = 1s. 6d) for the license. The license for a so-called machine-mine is about 1000 Kyats. The license cannot buy the land, which is only rented from the state for mining purposes. When mining operations are finished it is not necessary to fill in the craters and holes, contrary to practice in Ceylon. This is a defect in the law and leaves the valleys full of holes and unsuitable for agricultural purposes. For each employee the mine owner pays a monthly license fee of 10 Kyats and as a receipt obtains a small oval disc, which each miner must wear to facilitate inspection. Most mining is still done by hand with the help of water—without the local water supplies the mining could not have developed as it has.
Most of the stones are found in open-cast mines. The small narrow holes are widened with sticks and spades. The earth is put into woven bamboo baskets and lifted to the surface where it is emptied onto a heap. When the ruby-containing-the byons layer is reached, a byon heap is started, whence the earth is transported to the washing hole. Within a few weeks the small hole has become a mine of about 100 meters in diameter, perhaps reaching a depth of 20-30 meters, when the water level is reached. From a neighboring water tank water is hosed over the byon layers. The softened earth is pumped, either electrically or with a petrol engine, to a washing plant built from wood or stone and measuring perhaps four square meters and consisting of a basin which is about ½ -1 meter deep and from which there is a step-like arrangement of locks. Usually the earth is mined during the afternoon and then worked and washed the following morning, so that the gem-containing byon earth can settle during the night. In the morning clear water is pumped into the basin, washing away the top layer of waste earth, whilst the heavier gems settle in a series of boxes. During this time the washers stir up the deposit, so that it may be rinsed with water and carried away to a lower lock. Starting at the top the washers scoop some of the deposit up with their hands and shake it in a rough wire-mesh sieve to get rid of the large stones, the finer and medium deposit is then put into a shallow basket, from which the so-called therbat is put on the sorting table. The sorter, who in the case of small mines is the same man as the owner, combs through the therbat with a wooden comb and picks out the rubies. Just as the washing of the deposit below the last lock is free to everybody, so friends and relatives look through the waste from the sorting table either without remuneration or against a small fee. In this way all the innumerable small rubies which are used for adorning pieces of jewelry are won.
About 10 km west of Mogok, in the small township of Kathe and Kyatpyin, the valley is very dry and water not abundant and thus a new method of mining has developed. Parallel to each other long narrow trenches are dug, which are often connected under the surface by horizontal channels. These workings are usually co-owned by three to five men. At the opening of the shaft one or two winches are erected which help to bring to the surface the baskets which have been filled by a miner with the gem-containing earth or byon. The last man carries the basket either to the slack heap or the byon heap, which grows during the dry months from October to the end of April, and then is washed and worked during the summer monsoon season. Characteristic of the whole district is that there are no specially rich localities, but the precious stones can be found anywhere or everywhere, in a brook, in a rice field or in a mine. Ruby is the most looked for stone, but not the most common gem; there is one ruby found to every five spinels. There are fields which yield mainly rubies, other spinels, or moonstones or sapphires, and it has been known that certain mines produce certain colors, but in one basket of byon all types of unusual gems can be found. For the gem collector and gemologist the mines of Mogok are a real paradise, for apart from rubies, spinels, sapphires, moonstones and peridots, which are found in quantities, one also finds almandine garnets, amethysts, beryls, chrysoberyls, spessartites, topazes, tourmalines, zircons and citrines and mentioning some rare gems the following have been found as well: amblygonite, blue apatite, danburite, diopside, disthene, enstatite, violet fluorite, fibrolite, iolite, kornerupine, scapolite, titanite and others. The inhabitants of the districts know very little of these various gem types, and it is not surprising that one is often offered these stones under a wrong name. For instance, pink scapolite is known as pink moonstone and every yellow to brown stone as topaz. But if one knows anything about these stones, and in addition even possesses a refractometer, one can enrich a collection with many beautiful and rare specimens. There is a trade with rough rubies everywhere, along the mines, along the streets, in the bazaars, in the market places, in the backyards, and, of course, in the houses of the mine owners and gem dealers. Because there are always people looking on, a sign language using the fingers has been developed, with which one can express all numerals. Offers and acceptances are communicated under a cloth or in the wide sleeves of the engyis worn by the natives, so that none of the onlookers and strangers are any the wiser.
A large part of the gems found in Mogok and surrounding district are cut locally. Taking into account the very primitive grinding wheels the quality of the produced goods is fairly good, and quite usable according to Western standard. Depending on the resulting style the cutter chooses his tools and his method. Small stones, which are made into small cabochons, are usually worked by children and young girls. The rough stones are fixed onto a bamboo stick; five to ten of these sticks are held in each hand, then held onto a horizontally rotating grinding wheel. It is most instructive and enjoyable to watch how the hands lead the sticks on the wheel and how a few minutes later a number of cabochons are produced.
Large cabochons and star stones are produced by men who use special grinding boards with a carborundum covering; these boards have grooves of various widths in them which are also covered with various grades of carborundum. The rough stones are again fixed on bamboo sticks, which are pushed forwards and backwards in these grooves using finer and finer carborundum until the finished cabochons show a smooth highly polished surface.
The smaller facets are made by young boys, girls and women. The stones are fixed in a simple dop and the first facets are ground roughly on a carborundum board. After they have received their first rough shape they are fixed again onto sticks which can be held in a simple dop. The facets are then cut and polished on horizontally rotating grinding wheels, and from time to time checked by eye to ensure that they are even.
The large faceted stones are produced by a similar method, but only older and experienced cutters are allowed to make them. The advice of these cutters is welcomed by owners and dealers alike. The grinding wheels are rotated with the feet by a sort of treadle arrangement, as the old-fashioned electricity plant is not powerful enough to work all the wheels. Special large crystals are sometimes sawn before being cut and polished. In the whole of the district there is only one specialist who does this; he uses a machine which looks similar to an old sewing machine. It has a horizontal spindle on which a diamond sawing wheel is rotated by a foot pedal. Although the tools of their trade are primitive, most cutters are masters of their craft and know how to obtain the best results from an irregularly colored stone, or how to place inclusions or cracks in the stone into a position where it is extremely difficult to see them. Often stones with cracks are put into peanut oil so that cracks become invisible. It is also amazing how the Mogok cutters produce stones with even facets and regularity of geometrical planes. All these points show that their technical knowledge is greater than that of the Ceylonese cutters.
The buying of gems in Mogok is a time consuming but very interesting business, which needs absolute concentration and denial of western habits. It takes a long time for one to meet the people who sell the goods one wishes to buy. Once one has found them it needs a lot of patience until the stones are shown. Of the thousands of stones which are shown, only a few are of really good gem quality. Doubtless the families keep the very best stones to themselves and evens in Burma have shown the wisdom of this. But now and then a very fine gem is offered for sale. When the author was in Mogok, only after days of bargaining did the most important dealers show him a really good ruby or sapphire. The author was thus very impressed by the rarity and value of the finest gems. Most dealers show many lots of smaller and medium as well as a few larger rubies, but these lots are only shown one at a time, and much time and patience is needed to look through them all and wait for the appearance of better stones. The deal is never finalized without the wife giving her consent. The women of Mogok not only wear the jewels, they are also important in the mining, production and trade. In fact, the female gem merchants in Mogok are much tougher than the men and understand the fine qualities especially well.
The unit of weight is not the carat, but the Burmese rattie (1rt = 0.90 cts). The price of fine rubies has risen very sharply during the last 15 years. This has been caused not only by the increase in rarity, but also by the purchases of Indian merchants who pay too high a price for the rubies, as they earn some money on the transaction of the rupee-Kyat exchange. The inflationary and political uncertainities in Burma also play a part. The Burmese government is nationalizing all industries and has now also forbidden private businesses such as gem mining and dealing. The gem production is guarded by the army and all gems have to be sold to the Petrol and Mineral Development Corporation. The PMDC has now tried to sell the gems on the western markets, but was unsuccessful because of the low quality offered. During the first half of last December 180 gem dealers from 25 countries were invited to an officially organized sale, but most of these visitors were disappointed because of the poor quality offered to them. Many did not purchase anything as the poor qualities cannot be resold on the western markets. It seems a pity that most important gem producing countries have made free trading so difficult. For these countries the loss is usually only a few percent, while the loss in the free world is quite noticeable. These circumstances do not help to make the gems any cheaper, and every jeweler who has a few fine specimens is proud of them and knows how to treasure them.
(via The Journal of Gemmology, Vol.IX,No.12, October 1965) E Gubelin writes:
The ruby mines in Burma have been known for centuries and the large mining district of Mogok above a lovely lake has always proved to be of great interest because of the wonderful rubies found there. Mogok itself is full of mysteries and whoever goes there for the first time is delighted with its beautiful streets and the soft music of the bells from the temples and pagodas. The author visited this valley for the first time three years ago, after his second stay in Ceylon, and was in no way disappointed.
The western mountainous Shan-plateau rises towards the east over the middle Irrawaddy valley; there are mountains in the north and the lake to the south. The valley of rubies is narrow and long and towards its lower end lies Mogok. It is about 700 km north of Rangoon and 150 km north-east of Mandalay, the last residential town of the Burmese kings. Only 145 km east of this town is the frontier of Burma with China. The township lies about 1500 meters above sea level and is surrounded by mountainous sometimes reaching a height of 2500 meters, all covered with thick jungle. The climate is agreeable, although there is a great difference of temperature between the very hot hours around noon and the cold nights. It rains often and rainfall during the summer months of the monsoon can reach more than 250 mm. It is very rare that the temperature during the winter drops to freezing point.
At the time of writing the visa given to foreigners does not exceed 24 hours, which makes it impossible to leave Rangoon, but before this additional difficulty arose, there were several ways of going to Mogok. Mandalay can be reached by a slow train taking two days for the trip or by a four to six hour flight by the Union of Burma Airways. From Mandalay there are again several ways of reaching Mogok. One can fly on to Momeik and if one has any friends in Mogok ask them to fetch one by jeep. One then travels along a good mountainous road. But as it was well known that many robberies occurred at the time of the visit, the author thought it safer to use the official coach. The coach uses many dusty roads, full of ox-carts, along the Irrawady valley on a very bumpy road and then slowly rises on a narrow but good road through beautiful mountain country towards Mogok, where it arrives twelve hours later. Four days after the author’s safe arrival three private jeeps traveling down the valley were ambushed and robbed.
There are neither hotels nor boarding houses in Mogok, and if one wants to stay in a bungalow for government officials, one has to supply one’s own bed linen and either cook one’s meals, or eat in one of the small Chinese stalls. The author was very lucky and was invited to stay in the house of his Burmese interpreter and agent and was thus able to take part in the daily life of the family. They were all very kind and hospitable and tried to make the visit as agreeable as possible. There are only a few streets in Mogok, the most important being macadamed and at their sides are beautiful houses. Most of these are made of wood, some using teak. In the last few years a few villas were erected from stone. Around the town and in the surrounding villages the houses are made of interwoven bamboo sticks, build on piles. These airy rooms usually form the workshop and the gems are polished here. Unfortunately only the older houses are covered with straw, tiles or brick, the newer houses being covered with corrugated metal sheets, which are not attractive. Many small shops and stalls along the two main roads form the business quarter, where one can buy most consumer goods from a tea cup to a loupe or a washing basket made of bamboo strips to household articles made of plastic. Of the greatest interest is the bazaar, where there is a market every five days and the inhabitants of the surrounding districts and mountains gather in their colorful costumes to sell vegetables, herbs, baked articles, tobacco and all sorts of homemade goods and who seldom return home without looking at, or even buying a few rubies. One must also mention the waterworks and sewage arrangements, which work very well, and a very old-fashioned electricity plant which sells its electricity (220V) during the day to the mines and only after 6 pm to the townspeople, so that one can only then use the electric light. It is then used so much that the voltage falls from 220V to 110, so that one can hardly read. The foreign visitor is well advised to take a torch along together with a sufficient supply of batteries. There is no official waste disposal, so it is not surprising that there are often cases of malaria, dysentery and typhoid. The visitor must be careful in every respect. Apart from various nature-cures and quacks, there are also a few good doctors in Mogok, but hospitals, old people’s homes and orphanages are not necessary since all these services are given by the family. There is always much life in the streets. Most goods are still transported on a shoulder-yoke or by ox-cart. There are many bicycles, and a few cars and vans. The riche mine owners have land-rovers, and there are various jeeps which are used as taxis to which transport people to the surrounding villages.
Although the whole district is only a few square miles and Mogok itself only a small town, there must be about 20000 people living in the district. The inhabitants are very mixed: apart from Burmese, there are Ghurkas, Hindus, Chinese and the romantic looking people from the Schan tribe. On each side of the street, in market places, in front of the tea houses and bazaars, there are small groups of squatting women showing each other small brass bowls with rubies. One soon has the impression that the whole population from the earliest youth to the oldest age is involved in the prospecting, production and sale of rubies, whether as a mine worker, mine owner, gem merchant, polisher, host or tradesman. The people are very friendly, helpful and open: the few that speak a foreign language like to talk to visitors.
The famous ruby mines are secondary deposits, that is, they have been brought down into the valley from decomposed primary deposits. Such alluvial deposits are found in most of the smaller and larger valleys of the district, and everywhere there is prospecting for rubies. Mogok lies in the lower part of a larger valley on what used to be the most profitable deposits. When the population realized this, they moved their township to the lower part of the hills so that they could mine the rubies in the valley. When there were no rubies, the craters which were formed by the mining operations filled with water, forming the lovely Mogok Lake, which today beautifies the valley. In the neighboring valleys the yellow clay is full of holes, and looks like a volcanic field of craters.
Prospecting and mining licenses are only given to Burmese. The owner who wants to open a small mine registers his intention with the district officer, who examines the claim. Depending on the size of the mine, the owner pays several hundred Kyats (1 Kyat = 1s. 6d) for the license. The license for a so-called machine-mine is about 1000 Kyats. The license cannot buy the land, which is only rented from the state for mining purposes. When mining operations are finished it is not necessary to fill in the craters and holes, contrary to practice in Ceylon. This is a defect in the law and leaves the valleys full of holes and unsuitable for agricultural purposes. For each employee the mine owner pays a monthly license fee of 10 Kyats and as a receipt obtains a small oval disc, which each miner must wear to facilitate inspection. Most mining is still done by hand with the help of water—without the local water supplies the mining could not have developed as it has.
Most of the stones are found in open-cast mines. The small narrow holes are widened with sticks and spades. The earth is put into woven bamboo baskets and lifted to the surface where it is emptied onto a heap. When the ruby-containing-the byons layer is reached, a byon heap is started, whence the earth is transported to the washing hole. Within a few weeks the small hole has become a mine of about 100 meters in diameter, perhaps reaching a depth of 20-30 meters, when the water level is reached. From a neighboring water tank water is hosed over the byon layers. The softened earth is pumped, either electrically or with a petrol engine, to a washing plant built from wood or stone and measuring perhaps four square meters and consisting of a basin which is about ½ -1 meter deep and from which there is a step-like arrangement of locks. Usually the earth is mined during the afternoon and then worked and washed the following morning, so that the gem-containing byon earth can settle during the night. In the morning clear water is pumped into the basin, washing away the top layer of waste earth, whilst the heavier gems settle in a series of boxes. During this time the washers stir up the deposit, so that it may be rinsed with water and carried away to a lower lock. Starting at the top the washers scoop some of the deposit up with their hands and shake it in a rough wire-mesh sieve to get rid of the large stones, the finer and medium deposit is then put into a shallow basket, from which the so-called therbat is put on the sorting table. The sorter, who in the case of small mines is the same man as the owner, combs through the therbat with a wooden comb and picks out the rubies. Just as the washing of the deposit below the last lock is free to everybody, so friends and relatives look through the waste from the sorting table either without remuneration or against a small fee. In this way all the innumerable small rubies which are used for adorning pieces of jewelry are won.
About 10 km west of Mogok, in the small township of Kathe and Kyatpyin, the valley is very dry and water not abundant and thus a new method of mining has developed. Parallel to each other long narrow trenches are dug, which are often connected under the surface by horizontal channels. These workings are usually co-owned by three to five men. At the opening of the shaft one or two winches are erected which help to bring to the surface the baskets which have been filled by a miner with the gem-containing earth or byon. The last man carries the basket either to the slack heap or the byon heap, which grows during the dry months from October to the end of April, and then is washed and worked during the summer monsoon season. Characteristic of the whole district is that there are no specially rich localities, but the precious stones can be found anywhere or everywhere, in a brook, in a rice field or in a mine. Ruby is the most looked for stone, but not the most common gem; there is one ruby found to every five spinels. There are fields which yield mainly rubies, other spinels, or moonstones or sapphires, and it has been known that certain mines produce certain colors, but in one basket of byon all types of unusual gems can be found. For the gem collector and gemologist the mines of Mogok are a real paradise, for apart from rubies, spinels, sapphires, moonstones and peridots, which are found in quantities, one also finds almandine garnets, amethysts, beryls, chrysoberyls, spessartites, topazes, tourmalines, zircons and citrines and mentioning some rare gems the following have been found as well: amblygonite, blue apatite, danburite, diopside, disthene, enstatite, violet fluorite, fibrolite, iolite, kornerupine, scapolite, titanite and others. The inhabitants of the districts know very little of these various gem types, and it is not surprising that one is often offered these stones under a wrong name. For instance, pink scapolite is known as pink moonstone and every yellow to brown stone as topaz. But if one knows anything about these stones, and in addition even possesses a refractometer, one can enrich a collection with many beautiful and rare specimens. There is a trade with rough rubies everywhere, along the mines, along the streets, in the bazaars, in the market places, in the backyards, and, of course, in the houses of the mine owners and gem dealers. Because there are always people looking on, a sign language using the fingers has been developed, with which one can express all numerals. Offers and acceptances are communicated under a cloth or in the wide sleeves of the engyis worn by the natives, so that none of the onlookers and strangers are any the wiser.
A large part of the gems found in Mogok and surrounding district are cut locally. Taking into account the very primitive grinding wheels the quality of the produced goods is fairly good, and quite usable according to Western standard. Depending on the resulting style the cutter chooses his tools and his method. Small stones, which are made into small cabochons, are usually worked by children and young girls. The rough stones are fixed onto a bamboo stick; five to ten of these sticks are held in each hand, then held onto a horizontally rotating grinding wheel. It is most instructive and enjoyable to watch how the hands lead the sticks on the wheel and how a few minutes later a number of cabochons are produced.
Large cabochons and star stones are produced by men who use special grinding boards with a carborundum covering; these boards have grooves of various widths in them which are also covered with various grades of carborundum. The rough stones are again fixed on bamboo sticks, which are pushed forwards and backwards in these grooves using finer and finer carborundum until the finished cabochons show a smooth highly polished surface.
The smaller facets are made by young boys, girls and women. The stones are fixed in a simple dop and the first facets are ground roughly on a carborundum board. After they have received their first rough shape they are fixed again onto sticks which can be held in a simple dop. The facets are then cut and polished on horizontally rotating grinding wheels, and from time to time checked by eye to ensure that they are even.
The large faceted stones are produced by a similar method, but only older and experienced cutters are allowed to make them. The advice of these cutters is welcomed by owners and dealers alike. The grinding wheels are rotated with the feet by a sort of treadle arrangement, as the old-fashioned electricity plant is not powerful enough to work all the wheels. Special large crystals are sometimes sawn before being cut and polished. In the whole of the district there is only one specialist who does this; he uses a machine which looks similar to an old sewing machine. It has a horizontal spindle on which a diamond sawing wheel is rotated by a foot pedal. Although the tools of their trade are primitive, most cutters are masters of their craft and know how to obtain the best results from an irregularly colored stone, or how to place inclusions or cracks in the stone into a position where it is extremely difficult to see them. Often stones with cracks are put into peanut oil so that cracks become invisible. It is also amazing how the Mogok cutters produce stones with even facets and regularity of geometrical planes. All these points show that their technical knowledge is greater than that of the Ceylonese cutters.
The buying of gems in Mogok is a time consuming but very interesting business, which needs absolute concentration and denial of western habits. It takes a long time for one to meet the people who sell the goods one wishes to buy. Once one has found them it needs a lot of patience until the stones are shown. Of the thousands of stones which are shown, only a few are of really good gem quality. Doubtless the families keep the very best stones to themselves and evens in Burma have shown the wisdom of this. But now and then a very fine gem is offered for sale. When the author was in Mogok, only after days of bargaining did the most important dealers show him a really good ruby or sapphire. The author was thus very impressed by the rarity and value of the finest gems. Most dealers show many lots of smaller and medium as well as a few larger rubies, but these lots are only shown one at a time, and much time and patience is needed to look through them all and wait for the appearance of better stones. The deal is never finalized without the wife giving her consent. The women of Mogok not only wear the jewels, they are also important in the mining, production and trade. In fact, the female gem merchants in Mogok are much tougher than the men and understand the fine qualities especially well.
The unit of weight is not the carat, but the Burmese rattie (1rt = 0.90 cts). The price of fine rubies has risen very sharply during the last 15 years. This has been caused not only by the increase in rarity, but also by the purchases of Indian merchants who pay too high a price for the rubies, as they earn some money on the transaction of the rupee-Kyat exchange. The inflationary and political uncertainities in Burma also play a part. The Burmese government is nationalizing all industries and has now also forbidden private businesses such as gem mining and dealing. The gem production is guarded by the army and all gems have to be sold to the Petrol and Mineral Development Corporation. The PMDC has now tried to sell the gems on the western markets, but was unsuccessful because of the low quality offered. During the first half of last December 180 gem dealers from 25 countries were invited to an officially organized sale, but most of these visitors were disappointed because of the poor quality offered to them. Many did not purchase anything as the poor qualities cannot be resold on the western markets. It seems a pity that most important gem producing countries have made free trading so difficult. For these countries the loss is usually only a few percent, while the loss in the free world is quite noticeable. These circumstances do not help to make the gems any cheaper, and every jeweler who has a few fine specimens is proud of them and knows how to treasure them.
Problems In Burma
2007: What a clever way to learn about gemstone pricing!
(via Journal of Gemmology, Vol.IX, No.10, April, 1965)
One way of obtaining a valuation of gems is reported in the February 1965 Lapidary Journal. An extract says:
Recently the present Burmese government, which is completely Communistic in its national policies, held a purported auction sale of seized gems in Rangoon from 1st December to 12th December. Supposedly the ordinary passport and visa regulations were relaxed for this purpose in order to attract foreign gem experts. The sale, it was said, was meant only for gem dealers and stone sellers.
Reliable persons who were inveigled to attend from outside Burma have now returned disappointed and report that the whole things was fake. The government only wanted to get a free appraisal of the gems from gem experts and dealers through written bids on each item of gemstones. This seems to be the only purpose of such a fake sale. Persons who made offers in writing were answered by slips under their hotel room doors stating that the gems they bid on were not for sale. Many persons complained about losing their valuable time and their own transportation money in this deal.
It is widely known that the gem mines of Burma have been nationalized, that is, seized by the Communistic dominated government authorities and that all former owners have been dispossessed, particularly and especially the Chinese who owned the principal gem mines in the ruby district of Mogok and in the jadeite regions of Upper Burma.
(via Journal of Gemmology, Vol.IX, No.10, April, 1965)
One way of obtaining a valuation of gems is reported in the February 1965 Lapidary Journal. An extract says:
Recently the present Burmese government, which is completely Communistic in its national policies, held a purported auction sale of seized gems in Rangoon from 1st December to 12th December. Supposedly the ordinary passport and visa regulations were relaxed for this purpose in order to attract foreign gem experts. The sale, it was said, was meant only for gem dealers and stone sellers.
Reliable persons who were inveigled to attend from outside Burma have now returned disappointed and report that the whole things was fake. The government only wanted to get a free appraisal of the gems from gem experts and dealers through written bids on each item of gemstones. This seems to be the only purpose of such a fake sale. Persons who made offers in writing were answered by slips under their hotel room doors stating that the gems they bid on were not for sale. Many persons complained about losing their valuable time and their own transportation money in this deal.
It is widely known that the gem mines of Burma have been nationalized, that is, seized by the Communistic dominated government authorities and that all former owners have been dispossessed, particularly and especially the Chinese who owned the principal gem mines in the ruby district of Mogok and in the jadeite regions of Upper Burma.
New Fund Will Add Greater Liquidity to the Multi-Million Dollar Stones Market
Chaim Even-Zohar writes about liquidity crunch in the diamond industry + capital raising efforts via derivatives, futures markets, securitization and hedge funds to other schemes + commodity investment management firm and Swiss-based Diapason + the funds concept of aiming at the high end of the market + other viewpoints @ http://www.idexonline.com/portal_FullEditorial.asp
Light Generates Electricity
(via National Geographic Magazine) Light generates electricity with the aid of crystals, a boon to camera fans and space scientists. When sunlight strikes the crystalline selenium in a light meter or the silicon solar cells on a satellite, electrons in the crystals become activated, providing the current that powers the meter and satellite.
Friday, June 29, 2007
The Art Of Failure
Malcolm Gladwell writes about performance studies + why some people choke and others panic @ http://www.gladwell.com/2000/2000_08_21_a_choking.htm
Threads: Their Types And Some Of Their Characters
(via The Journal of Gemmology, Vol 12, No.7, July 1971) Robert Webster writes:
For some time it has been the writer’s intention to consider some aspects of the nature of threads used to string pearls and beads into necklets, for the subject, which one might readily admit is not gemology proper, does have some importance in answering questions sometimes posed to a laboratory.
The reason which has prompted further investigation into this sphere devolved from some remarks made by the late Dr V B Meen, of Canada, after the writer had read a paper on damage to gemstones at the XIIIth International Gemmological Conference held at Brussels in 1970. During this talk the blackening of some cultured cultured pearls by the action of cosmetic creams was mentioned.
Dr Meen asked if any attention had been paid to the type of thread which had been used in stringing the pearls in the case mentioned, as some types of thread were more prone to attract grease than others. It was possible to show that in the records of this case there was a note to the effect that the string did not appear to be normal, but that this aspect was not pursued.
There may be other problems, too, where some information on the nature of the string used in threading beads may well be needed. This article is an attempt to give a short survey and to provide a basis for any future investigation. It will be readily seen that any full-scale investigation on the types and characters of threads would be a long-term project, but one which might well be worthwhile.
According to Walls threads, the more scientific name being fibres, can be classified into four groups as follows:
1. Animal hairs such as wool, mohair (Angora goat), camel, none of which have any place in the present study.
2. Vegetable fibres, which are divided into two groups. (a) Seed hairs, such as cotton and kapok, cotton being the only one which needs consideration here. (b) Bast and structural fibres; these are exemplified by flax (linen), jute, hemp and sisal. Only flax is of interest.
3. Fibres produced by the solidification of a liquid extruded through a fine orifice; these are again subdivided into sub-groups:-
(a) Natural, of which silk is the only important member.
(b) Artificial (man-made); there are two well defined groups:-
(i) Those made from animal or vegetable raw materials, such as regenerated cellulose (Rayon); cellulose esters, usually acetate (Tricel, Arnel, Trilon); alginates (from seaweed); regenerated proteins (casein) and others.
(ii) Purely synthetic fibres: such as polyolefines (polyethylene, etc); polyamides (Nylon, Brilon); polyesters (e.g. Terylene—Dacron in the United States of America—a polyethylene terephthalate); acrylonitrile polymers (Orlon, Acrilan, Courtelle, etc); vinyl chloride and vinylidene chloride polymers (Vinyon, Saran, and others).
4. Miscellaneous fibres; such fibres are natural mineral fibres (asbestos) and fibres of glass, metal, etc. which have no place in this study.
Of these numerous fibres, most of which are used in the textile industry, the only ones which need to be discussed are silk, cotton, linen, and some of the artificial fibres, particularly Nylon.
Silk
The most important fibre used for pearl stringing, silk is produced by the caterpillar of the moth Bombyx mori, which, when fully grown, spins a cocoon with a secretion produced by the caterpillar from a pair of tubular spinning glands. Each of these glands produces a single fibre, which is at first in a fluid condition.
These two fibres are then, by muscular action, and possibly aided by another secretion, formed into a single thread. This is silk, an albumoid, and the fibres normally receive certain cleaning treatments before being spun and woven into fabrics.
When a flame is applied to the end of a silk thread it burns, but does not readily flame, and the thread forms a shriveled blob. The flame does not tend to travel along the thread and is quickly extinguished. Under the microscope the threads are seen to be more or less structureless cylindrical rods which at places may flatten or bulge out. The fluorescence varies considerably due, as mentioned by Radley and Grant, to the fact that dressing agents, oils and dyestuffs, often completely alter the color of the fluorescence, and these writers also state that small traces of fluorescent dyestuffs added as brightening agents may produce complicating effects in ultraviolet light. Fluorescence can have scant discriminative value in the detection of the fibres themselves.
Cotton
Threads of cotton are not normally used for pearl stringing but some mention is included in this survey for there is reason to believe that they have been used for such a purpose, and, further, they are certainly used for stringing necklets of amber, coral, jet and some ornamental stones, such as malachite and rhodonite. Star sylko or Clark’s anchor stranded embroidery silks are often used for stringing such necklets.
The most important of the vegetable fibres, cotton, consists of white or yellowish-colored fibres which are obtained from the seeds of various species of the genus Gossypium of the order Malvaccae. Well bleached cotton is said to be nearly pure cellulose.
When a flame is applied to cotton threads they readily burn with the flame traveling along the thread leaving very little ash. On extinction of the flame the glowing embers emit a smell of burnt wood. When fibres of raw cotton are examined under the microscope the general appearance resembles that of a wrinkled, twisted irregular ribbon which may be likened to an exhausted rubber tubing. After treatment, such as mercerizing, which imparts a luster to the cotton so that it resembles to some extent silk, the typical appearance of the threads may not be so apparent under magnification.
Linen
The name is derived from the flax plant Linum usitatissimum, which is pulled just after flowering. The linen fibre, being the first layer under the epidermis of the stalk is separated from the rest of the stalk by retting in stagnant or running water. Following this the mucilaginous substances contained in the flax are removed by suitable treatments.
Like cotton, linen burns fairly readily with, on extinction, a smell of smoldering wood. Examined under the microscope the central canal is not so marked as in cotton and the fibre has notches at irregular intervals, and, further, may show diagonal striations. Linen lacks the convolutions shown by cotton fibres.
Artificial fibres
The beginning of the artificial fibre industry began with the work of Count Hilaire de Chardonnet of France during the 1880’s, although as early as 1665 the idea of making artificial silk was mooted by Robert Hooke. Chardonnet’s silk was nitrated cellulose, a type of celluloid, and was far too inflammable and, indeed, the sale of this silk was eventually banned in France.
The next advance in the production of artificial silks was due to the work of C F Cross and E J Bevan, who produced the rayons. These fibres were and are produced by regenerating cellulose. Plant cellulose, such as cotton linters, wood-pulp, are chemically dissolved and then regenerated and extruded through a diaphragm pierced with very fine orifices called spinnerette. Such regenerated cellulose fibres are Viscose rayon, cuprammonium rayon, and acetate rayon, but these fibres have little importance in this discussion.
The most important of the man-made fibres for this study is the super-polyamide called nylon, the production of which was the outcome of researches carried out by the American plastics chemist Carothers, aided by some of his colleagues. Made from hydrocarbons obtained from coal, and from ammonia, nylon, of which there are at least three types, is said to be twice as strong as silk and to be more elastic. It is probably due to this latter effect that nylon is not favored for pearl stringing as it does not knot well is inclined to stretch. There are two kinds of nylon cord which may be purchased for pearl and bead stringing. The first is made up of twisted fibres and resembles the true pearl silk, while the other, more used for beads than pearls, consists of a single strand, like a flexible rod. There is a variation of this latter type which is wound round with a spiral of fine metal wire and presumably used for heavy beads. If the single strand nylon cord is used for pearls or lightweight beads the necklet tends to bow and does not hand at all well.
Nylon melts before burning, producing a sticky blob which follows the flame traveling along the string. This blob of molten material, if dropped on to the skin, burns like hot fat. The flame of burning nylon is, however, readily extinguished. Nylons, like most of the other man-made fibres, are usually assumed to be structureless internally, but microscopical examination has shown that there appear to be masses of fine bubbles oriented parallel to the length of the fibre. This phenomenon seems to be more prominent in the case of nylon and this may be accounted for as nylon is extruded from a molten mass and not from a liquid which is expelled through the spinnerettes into a coagulating bath which solidifies the fibres.
In order to ascertain the probability of differential absorption of grease by various fibres a series of experiments were undertaken. A frame was constructed consisting of a length of channel aluminum, bored with eight small holes through both sides, which was screwed down to a suitable baseboard. The metal channel, intended to carry the grease, was closed at each end by aluminum angle plates. A series of different threads were then threaded through the holes in the channel and anchored so that they were fixed at the outer face of the channel. The threads then passed across the channel and across the baseboard for a distance of some 12 centimeters, where the ends were anchored to a fixed wooden strip by the aid of drawing pins. Suitable lettered labels were stuck down on the baseboard in order to identify the strands.
It was considered that suitable grease would be a cosmetic cream and Pond’s cold cream was used. To ascertain if the grease traveled along the string a small quantity of the chemical rhodamine was mixed with the cold cream, the notion being that it would not only give color to the but would show up under ultraviolet light, for rhodamine is highly fluorescent and glows with an orange or reddish brown light. During the experiment the frame was kept in a glass-topped box.
The strings used in the first experiment were as follows:
(a) Silk (dyed brown)
(b) Pearl silk
(c) Sylko mercerized cotton
(d) Linen thread
(e) Terylene thread
(f) Nylon (single thread)
(g) Spun nylon pearl silk (Nylcord)
(h) Clark’s anchor stranded embroidery cotton
The result observed after the grease had been placed in the channel was striking in that within an hour the grease had traveled down some of the threads, admittedly not very far but with significant differences. Strangely the seepage seemed to stop at these points and there was little further increase even after a week. The distances the grease, which colored the strings, had traveled along the strings were then measured, giving the following results:
(a) Dyed silk: no apparent effect
(b) Pearl silk: very weak seepage of about 1.5 mm
(c) Sylko mercerized cotton: 5mm
(d) Linen: 2mm
(e) Terylene: 4mm
(f) Nylon single cord: no effect
(g) Twisted nylon (Nylcord): 11mm
(h) Embroidery cotton: 3mm
The frame was then unstrung and the grease removed and kept, and the frame itself thoroughly cleaned and restrung with different threads as under:
(a) A fine tacking cotton
(b) Brown linen thread
(c) Terylene, same type of thread as in (e) in first run
(d) Pearl stringing silk. A different source from (b) above
(e) Pure silk (yellow dyed Regal)
(f) Polyethylene thread (blue dyed)
(g) Terylene (Coat’s white)
(h) Embroidery silk (cotton) as in (h) above
The cold cream plus rhodamine, which was removed from the channel after the first run, was then mixed with as much again of the cold cream but no more rhodamine added. Thus the concentration of rhodamine was only half that of the previous mixture.
After some hours the frame and threads were examined, but the results appeared to be disappointing, mainly because the lower concentration of rhodamine did not strikingly color the threads, and the fluorescence effects were masked by the strong whitish glow emitted by the threads themselves. However, some trace of differential seepage was apparent.
There was always the question of how much body heat would affect the mobility of grease in the case of a necklet worn for some time around the neck. To test this, the frame was removed from the glass-topped box and placed on a warm print dryer. This print dryer gave off much more heat than the heat given off by a human body, and, hence, the results obtained would be expected to be much more rapid, as, indeed they seemed to be as the following shows:
(a) Cotton thread: diffuse staining decreasing in intensity up to 5 to 6 cms
(b) Linen: a little staining up to 2 to 3 mm
(c) Terylene: slight tinting for practically the full length of the string
(d) Pearl silk: very slight staining for 3 to 4 cms
(e) Yellow dyed pure silk: very slight staining
(f) Polyethylene: color of the dyed thread precluded much in the way of observation or by fluorescence
(g) Terylene: weak staining for a considerable distance, and in fact seemed to behave rather like (c)
(h) Cotton embroidery silk: staining for about 15 mm
Note: the very slight staining of the Terylenes (c) and (g) could only be identified by comparison with thread taken from the original reels.
In conclusion, it may be said that the experiments have shown that there is some justification for the suggestion that there is differential absorption and percolation of grease along fibres of different natures. However, much more information is required and far more experimentation needs to be carried out on a greater number of kinds of fibres for a really full study of the subject. It seems apparent that twisted fibres tend to carry grease more readily than single strand material, as exemplified by the nylon samples tested. This was rather to be expected and most probably due to the greater possibility of capillary attraction between the threads.
Most of the threads carried grease for upwards of two millimeters, and as the nacreous shell of a cultured pearl is seldom more than a millimeter thick, it is clear that the grease would reach the discontinuation layer between the skin and the bead of the cultured pearl and tend to travel along it, as indeed, was found to have happened in the case mentioned at the beginning of this article.
What is further to be considered is that the experiments were carried out with static threads on a frame. There is movement of the beads on a necklet when it is worn and this would assist the grease to seep along the string. What does seem to be proved by the experiments is that silk is the best material to use in stringing natural and cultured pearls and to use other types of thread may well lead to trouble for the jeweler.
For some time it has been the writer’s intention to consider some aspects of the nature of threads used to string pearls and beads into necklets, for the subject, which one might readily admit is not gemology proper, does have some importance in answering questions sometimes posed to a laboratory.
The reason which has prompted further investigation into this sphere devolved from some remarks made by the late Dr V B Meen, of Canada, after the writer had read a paper on damage to gemstones at the XIIIth International Gemmological Conference held at Brussels in 1970. During this talk the blackening of some cultured cultured pearls by the action of cosmetic creams was mentioned.
Dr Meen asked if any attention had been paid to the type of thread which had been used in stringing the pearls in the case mentioned, as some types of thread were more prone to attract grease than others. It was possible to show that in the records of this case there was a note to the effect that the string did not appear to be normal, but that this aspect was not pursued.
There may be other problems, too, where some information on the nature of the string used in threading beads may well be needed. This article is an attempt to give a short survey and to provide a basis for any future investigation. It will be readily seen that any full-scale investigation on the types and characters of threads would be a long-term project, but one which might well be worthwhile.
According to Walls threads, the more scientific name being fibres, can be classified into four groups as follows:
1. Animal hairs such as wool, mohair (Angora goat), camel, none of which have any place in the present study.
2. Vegetable fibres, which are divided into two groups. (a) Seed hairs, such as cotton and kapok, cotton being the only one which needs consideration here. (b) Bast and structural fibres; these are exemplified by flax (linen), jute, hemp and sisal. Only flax is of interest.
3. Fibres produced by the solidification of a liquid extruded through a fine orifice; these are again subdivided into sub-groups:-
(a) Natural, of which silk is the only important member.
(b) Artificial (man-made); there are two well defined groups:-
(i) Those made from animal or vegetable raw materials, such as regenerated cellulose (Rayon); cellulose esters, usually acetate (Tricel, Arnel, Trilon); alginates (from seaweed); regenerated proteins (casein) and others.
(ii) Purely synthetic fibres: such as polyolefines (polyethylene, etc); polyamides (Nylon, Brilon); polyesters (e.g. Terylene—Dacron in the United States of America—a polyethylene terephthalate); acrylonitrile polymers (Orlon, Acrilan, Courtelle, etc); vinyl chloride and vinylidene chloride polymers (Vinyon, Saran, and others).
4. Miscellaneous fibres; such fibres are natural mineral fibres (asbestos) and fibres of glass, metal, etc. which have no place in this study.
Of these numerous fibres, most of which are used in the textile industry, the only ones which need to be discussed are silk, cotton, linen, and some of the artificial fibres, particularly Nylon.
Silk
The most important fibre used for pearl stringing, silk is produced by the caterpillar of the moth Bombyx mori, which, when fully grown, spins a cocoon with a secretion produced by the caterpillar from a pair of tubular spinning glands. Each of these glands produces a single fibre, which is at first in a fluid condition.
These two fibres are then, by muscular action, and possibly aided by another secretion, formed into a single thread. This is silk, an albumoid, and the fibres normally receive certain cleaning treatments before being spun and woven into fabrics.
When a flame is applied to the end of a silk thread it burns, but does not readily flame, and the thread forms a shriveled blob. The flame does not tend to travel along the thread and is quickly extinguished. Under the microscope the threads are seen to be more or less structureless cylindrical rods which at places may flatten or bulge out. The fluorescence varies considerably due, as mentioned by Radley and Grant, to the fact that dressing agents, oils and dyestuffs, often completely alter the color of the fluorescence, and these writers also state that small traces of fluorescent dyestuffs added as brightening agents may produce complicating effects in ultraviolet light. Fluorescence can have scant discriminative value in the detection of the fibres themselves.
Cotton
Threads of cotton are not normally used for pearl stringing but some mention is included in this survey for there is reason to believe that they have been used for such a purpose, and, further, they are certainly used for stringing necklets of amber, coral, jet and some ornamental stones, such as malachite and rhodonite. Star sylko or Clark’s anchor stranded embroidery silks are often used for stringing such necklets.
The most important of the vegetable fibres, cotton, consists of white or yellowish-colored fibres which are obtained from the seeds of various species of the genus Gossypium of the order Malvaccae. Well bleached cotton is said to be nearly pure cellulose.
When a flame is applied to cotton threads they readily burn with the flame traveling along the thread leaving very little ash. On extinction of the flame the glowing embers emit a smell of burnt wood. When fibres of raw cotton are examined under the microscope the general appearance resembles that of a wrinkled, twisted irregular ribbon which may be likened to an exhausted rubber tubing. After treatment, such as mercerizing, which imparts a luster to the cotton so that it resembles to some extent silk, the typical appearance of the threads may not be so apparent under magnification.
Linen
The name is derived from the flax plant Linum usitatissimum, which is pulled just after flowering. The linen fibre, being the first layer under the epidermis of the stalk is separated from the rest of the stalk by retting in stagnant or running water. Following this the mucilaginous substances contained in the flax are removed by suitable treatments.
Like cotton, linen burns fairly readily with, on extinction, a smell of smoldering wood. Examined under the microscope the central canal is not so marked as in cotton and the fibre has notches at irregular intervals, and, further, may show diagonal striations. Linen lacks the convolutions shown by cotton fibres.
Artificial fibres
The beginning of the artificial fibre industry began with the work of Count Hilaire de Chardonnet of France during the 1880’s, although as early as 1665 the idea of making artificial silk was mooted by Robert Hooke. Chardonnet’s silk was nitrated cellulose, a type of celluloid, and was far too inflammable and, indeed, the sale of this silk was eventually banned in France.
The next advance in the production of artificial silks was due to the work of C F Cross and E J Bevan, who produced the rayons. These fibres were and are produced by regenerating cellulose. Plant cellulose, such as cotton linters, wood-pulp, are chemically dissolved and then regenerated and extruded through a diaphragm pierced with very fine orifices called spinnerette. Such regenerated cellulose fibres are Viscose rayon, cuprammonium rayon, and acetate rayon, but these fibres have little importance in this discussion.
The most important of the man-made fibres for this study is the super-polyamide called nylon, the production of which was the outcome of researches carried out by the American plastics chemist Carothers, aided by some of his colleagues. Made from hydrocarbons obtained from coal, and from ammonia, nylon, of which there are at least three types, is said to be twice as strong as silk and to be more elastic. It is probably due to this latter effect that nylon is not favored for pearl stringing as it does not knot well is inclined to stretch. There are two kinds of nylon cord which may be purchased for pearl and bead stringing. The first is made up of twisted fibres and resembles the true pearl silk, while the other, more used for beads than pearls, consists of a single strand, like a flexible rod. There is a variation of this latter type which is wound round with a spiral of fine metal wire and presumably used for heavy beads. If the single strand nylon cord is used for pearls or lightweight beads the necklet tends to bow and does not hand at all well.
Nylon melts before burning, producing a sticky blob which follows the flame traveling along the string. This blob of molten material, if dropped on to the skin, burns like hot fat. The flame of burning nylon is, however, readily extinguished. Nylons, like most of the other man-made fibres, are usually assumed to be structureless internally, but microscopical examination has shown that there appear to be masses of fine bubbles oriented parallel to the length of the fibre. This phenomenon seems to be more prominent in the case of nylon and this may be accounted for as nylon is extruded from a molten mass and not from a liquid which is expelled through the spinnerettes into a coagulating bath which solidifies the fibres.
In order to ascertain the probability of differential absorption of grease by various fibres a series of experiments were undertaken. A frame was constructed consisting of a length of channel aluminum, bored with eight small holes through both sides, which was screwed down to a suitable baseboard. The metal channel, intended to carry the grease, was closed at each end by aluminum angle plates. A series of different threads were then threaded through the holes in the channel and anchored so that they were fixed at the outer face of the channel. The threads then passed across the channel and across the baseboard for a distance of some 12 centimeters, where the ends were anchored to a fixed wooden strip by the aid of drawing pins. Suitable lettered labels were stuck down on the baseboard in order to identify the strands.
It was considered that suitable grease would be a cosmetic cream and Pond’s cold cream was used. To ascertain if the grease traveled along the string a small quantity of the chemical rhodamine was mixed with the cold cream, the notion being that it would not only give color to the but would show up under ultraviolet light, for rhodamine is highly fluorescent and glows with an orange or reddish brown light. During the experiment the frame was kept in a glass-topped box.
The strings used in the first experiment were as follows:
(a) Silk (dyed brown)
(b) Pearl silk
(c) Sylko mercerized cotton
(d) Linen thread
(e) Terylene thread
(f) Nylon (single thread)
(g) Spun nylon pearl silk (Nylcord)
(h) Clark’s anchor stranded embroidery cotton
The result observed after the grease had been placed in the channel was striking in that within an hour the grease had traveled down some of the threads, admittedly not very far but with significant differences. Strangely the seepage seemed to stop at these points and there was little further increase even after a week. The distances the grease, which colored the strings, had traveled along the strings were then measured, giving the following results:
(a) Dyed silk: no apparent effect
(b) Pearl silk: very weak seepage of about 1.5 mm
(c) Sylko mercerized cotton: 5mm
(d) Linen: 2mm
(e) Terylene: 4mm
(f) Nylon single cord: no effect
(g) Twisted nylon (Nylcord): 11mm
(h) Embroidery cotton: 3mm
The frame was then unstrung and the grease removed and kept, and the frame itself thoroughly cleaned and restrung with different threads as under:
(a) A fine tacking cotton
(b) Brown linen thread
(c) Terylene, same type of thread as in (e) in first run
(d) Pearl stringing silk. A different source from (b) above
(e) Pure silk (yellow dyed Regal)
(f) Polyethylene thread (blue dyed)
(g) Terylene (Coat’s white)
(h) Embroidery silk (cotton) as in (h) above
The cold cream plus rhodamine, which was removed from the channel after the first run, was then mixed with as much again of the cold cream but no more rhodamine added. Thus the concentration of rhodamine was only half that of the previous mixture.
After some hours the frame and threads were examined, but the results appeared to be disappointing, mainly because the lower concentration of rhodamine did not strikingly color the threads, and the fluorescence effects were masked by the strong whitish glow emitted by the threads themselves. However, some trace of differential seepage was apparent.
There was always the question of how much body heat would affect the mobility of grease in the case of a necklet worn for some time around the neck. To test this, the frame was removed from the glass-topped box and placed on a warm print dryer. This print dryer gave off much more heat than the heat given off by a human body, and, hence, the results obtained would be expected to be much more rapid, as, indeed they seemed to be as the following shows:
(a) Cotton thread: diffuse staining decreasing in intensity up to 5 to 6 cms
(b) Linen: a little staining up to 2 to 3 mm
(c) Terylene: slight tinting for practically the full length of the string
(d) Pearl silk: very slight staining for 3 to 4 cms
(e) Yellow dyed pure silk: very slight staining
(f) Polyethylene: color of the dyed thread precluded much in the way of observation or by fluorescence
(g) Terylene: weak staining for a considerable distance, and in fact seemed to behave rather like (c)
(h) Cotton embroidery silk: staining for about 15 mm
Note: the very slight staining of the Terylenes (c) and (g) could only be identified by comparison with thread taken from the original reels.
In conclusion, it may be said that the experiments have shown that there is some justification for the suggestion that there is differential absorption and percolation of grease along fibres of different natures. However, much more information is required and far more experimentation needs to be carried out on a greater number of kinds of fibres for a really full study of the subject. It seems apparent that twisted fibres tend to carry grease more readily than single strand material, as exemplified by the nylon samples tested. This was rather to be expected and most probably due to the greater possibility of capillary attraction between the threads.
Most of the threads carried grease for upwards of two millimeters, and as the nacreous shell of a cultured pearl is seldom more than a millimeter thick, it is clear that the grease would reach the discontinuation layer between the skin and the bead of the cultured pearl and tend to travel along it, as indeed, was found to have happened in the case mentioned at the beginning of this article.
What is further to be considered is that the experiments were carried out with static threads on a frame. There is movement of the beads on a necklet when it is worn and this would assist the grease to seep along the string. What does seem to be proved by the experiments is that silk is the best material to use in stringing natural and cultured pearls and to use other types of thread may well lead to trouble for the jeweler.
Paying The Price For Suffering Banking Discord
Chaim Even-Zohar writes about M Fabrikant & Sons + the bankers + risk-mitigation strategies of banks + other viewpoints @ http://www.idexonline.com/portal_FullEditorial.asp?TextSearch=&KeyMatch=0&id=26543
Audio Slideshow: Sapphire Miners
BBC writes about Madagascar gemstone deposits, especially sapphires + other colored stones, with more than half the population living in miserable conditions @ http://news.bbc.co.uk/2/hi/in_depth/629/629/6230594.stm
Delicate Whiskers
(via National Geographic Magazine) Delicate whiskers each a single crystal of sapphire, possess amazing strength and heat resistance. Combined with metals, they form materials that may one day meet the structural demands of superlength suspension bridges and heat-plagued hypersonic aircraft.
Thursday, June 28, 2007
Treatment Of Verneuil Synthetic Corundum
Heat treatment of Verneuil synthetic corundum at temperatures of more than 1600°C can substantially reduce the visibility of curved color banding and striations (striae arise from fluctuations in the composition used for the feed in the flame fusion process). The high temperatures reached in the treatment process allow these impurities to diffuse, and become much less prominent. If the heating is irregular, with sudden temperature changes, small surface cracks can be developed at the surface of Verneuil synthetic corundums. If these cracked corundums are then packed in borax and heated once more, partial healing takes place, and some of the borax penetrates into surface fissures producing features very similar to those seen in natural ruby (Nassau). Many colored varieties of treated synthetic corundums are sold in the gem markets and mines around the world as natural. Even experienced gemologists make mistakes perceiving them to be natural.
Blowing Up
Malcolm Gladwell writes about Nassim Taleb + the way he turned the inevitability of disaster into an investment strategy @ http://www.gladwell.com/2002/2002_04_29_a_blowingup.htm
It's The Distribution – Stupid!
Chaim Even-Zohar writes about sight boxes + the pricing + rapidly growing diamond industry + the bad apples in the industry + other viewpoints @ http://www.idexonline.com/portal_FullEditorial.asp?TextSearch=&KeyMatch=0&id=26510
The Treasure Of The Moghul Emperors Of India
(via The Journal of Gemmology, Vol.12. No.3, July 1970) N Viswanath writes:
During the 16th and 17th centuries, India was ruled by the Emperors of the Moghul Dynasty. Of them, six were the most powerful and notable. They were: Babar, Humayun, Akbar, Jehangir, Shahjahan and Aurangzeb. With the death of the last Emperor, the dynasty began disintegrating.
It was during the reign of the last three Emperors that the wealth of the Moghuls was at its peak. Historians have been unable as yet to determine exactly how much the Moghul treasure was worth as some of it was looted by subsequent rulers of India.
Fortunately, Emperor Jehangir has left an authoritative account of his treasure and the list still exists. There was bullion in his treasury amounting to seven tons of gold, and 1116 tons of silver. Among precious stones, there were 80 pounds (more than 5,000,000 carats) of uncut diamonds, 100 pounds each of rubies and emeralds, and 600 pounds of pearls. “Of the other less important varieties of precious stones, the quantity is infinite,” says the document.
The royal armory included 2000 swords studded with diamond-encrusted handles, and the court furniture included 103 chairs of solid silver and five of solid gold. For high dignitaries and visiting monarchs, there were better seating arrangements. Five gorgeous thrones, two of gold and three of silver, were set apart for such persons. Emperor Jehangir himself had seven diamond-studded thrones besides the famous Peacock Throne.
Jehangir’s bathtub today, would be worth the ransom of a billionaire. It was seven feet by five feet in dimensions and was decorated with diamonds to relieve the drabness of gold.
His son Shahjehan, the fifth Moghul Emperor who built the world famous Taj Mahal at Agra was a great connoisseur himself. It was said of him that there was no jeweler in the East who could value precious stones better than he could and the emperor had all luck in pursuing his hobby. He had the first choice of the world’s richest diamond mines, the famous Goldconda fields, and only his rejections were allowed to circulate in the market.
Incidentally, until 1726 AD, the major sources of diamonds in the world were the Golconda mines in India. The Pitt, the Regent, and the Kohinoor are a few of the historic diamonds that owe their origin to Golconda.
Sir Thomas Roe, the British Ambassador to Emperor Shahjehan’s Court, knew to his cost that there could no trifling with the Emperor. Sir Thomas had something like the mythical Unicorn’s horn to palm off. Knowing Shahjehan’s weakness for rare treasure, Sir Thomas tried some sales talk with the Emperor saying that he was offering the horn to him only because the Emperor was the person to appreciate its value.
The horn was supposed to have the rare property of neutralizing any poisonous liquid and as such was considered to be a very welcome gift to sovereigns like Shahjehan, whose life was always in constant danger from enemies. He had hoped this would induce the Emperor to pass it at a high price.
But the shrewd Emperor knew that the horn was not worth the price quoted. He merely thanked the Ambassador and dropped the subject with a courteous expression. The diplomat had to find some other gullible purchaser, and finally, it was disposed of at a cheap price to a Dutch captain.
Shahjehan was no hoarder and often gave away fabulous gems as outright gifts. One day, a diamond brighter than the Pole Star came to his hands from the Golconda mines and the bulwark of Islam as Shahjehan like to call himself, decided that this would be a worthy gift to the Prophet’s Mosque at Mecca. He immediately ordered that a gold candelabra weighing 14 pounds be selected, embellished it with the brighter than the Pole Star diamond, and had it sent post-haste to Mecca. Today, a conservative value of the gift would be about ten million rupees.
Imperial wars also brought treasures to the royal jewel box. When the Moghul forces invaded his domain during the early part of Shahjehan’s reign, the King of Golconda found it advisable to make a peace offering. He sent 200 caskets of jewels to placate the Emperor. But the unfortunate King did not escape his fate. With avarice kindled at the gift, Shahjehan ordered his troops to advance, and they returned with booty exceeding 300 million rupees in value.
No historian could make a correct estimate of Shahjehan’s wealth of which it was said that it was greater than that of his nearest rivals, the Emperors of France and Persia, put together.
But then, there had to be a place to keep all his booty. One fine morning, the Emperor was told by the Master of the Treasury that it was choking with jewels, and that something had to be done to the strong room to relieve the congestion. The Emperor mused for a while. The problem was finally solved by the creation of the famous Peacock Throne. In the late 17th century when it was made, the Throne was valued at an amount equivalent to 530 million rupees. The Throne was completed after seven years of unceasing labor by the Emperor’s best craftsmen.
The plate and cutlery of Shahjehan’s palace weighed 25 tons of gold and 50 tons of silver, respectively. The mere gold content of the plate would today be worth more than 15 million rupees.
In one of his tributes to Shahjehan, Sir Thomas Roe has remarked that the King of Bijapur sent to the Emperor 36 elephants, two of which were adorned with gold chains weighing 400 pounds. There were 50 horses in the gift with trappings worth five million rupees. All possible care was taken that the precious stones were properly graded according to the exacting imperial specifications. For example, the diamonds were divided into 12 categories while pearls were of 16 varying grades.
The draperies of the palace were valued at ten million rupees, and the furnishings include chinaware to the value of 2,500,000 rupees. All the porcelain was imported from China under a special order from the Emperor and was among the best in the era.
The Moghul Emperors were so particular about chinaware that once when a high-ranking officer of the imperial household broke a matching piece of porcelain dish, Emperor Aurangazeb behaved as roughly as an ordinary housewife. He was on a tour of his domains in South India when the hapless official dropped the fruit dish in the capital, Delhi, about 1000 and odd miles away from the Emperor. The culprit knew full well that his carelessness would bring a halter round his neck and at once dispatched a messenger to China to bring back a similar dish to complete the set. He had hoped that the dish would reach Delhi before the Emperor returned from his tour. Unfortunately for him, the Emperor returned far ahead of the schedule, and in course of time, wanted his favorite fruit dish. The trembling official related the accident, and in view of the fact that arrangements had already been made to get a replacement, the official was temporarily excused and suspended pending arrival of the caravan from China.
But the notorious Central Asian robbers made short work of the messengers and the money they carried for purchase of the chinaware. When the period of grace elapsed and there was no news from China, the irate Emperor gave the official the choice between immediate execution and that of going to China to get the porcelain dish.
The official chose the latter course and began the hazardous journey to Cathay (China). As his whole family was held as hostages by the Emperor, he had to be particularly careful about his life and chose the safe route through the Pamir mountains, the so-called backbone of the world. The ranges of the Pamir tower to a height of about 23000 feet and one can very well imagine the plight of the official. Fortunately, Heaven took pity on him and the story of this official reached the court of the then Persian Emperor. This monarch ordered his Grand Wazier to look in the royal Persian cupboards to find whether there was any porcelain dish to match the one for which the official was searching. Happily, such a piece was found, and the Persian Emperor ordered that a gift of this porcelain dish be made to the official. But the poor man was so much broken down in health from the rigors of the journey that he died en route by the time deliverance came.
Emperor Shahjehan did not keep all his treasures in one place. They were divided in varying proportions and were kept in fortresses in different parts of the empire. There were seven of these treasure forts, besides the capital of Delhi. They were Gwalior, Marwar, Lahore, Rantambher, Asirgarh, Rohstsagar, and of course, Agra. The Lahore fort contained the maximum quantity of bullion, while Agra, as the Emperor’s favorite citadel, held most of the jewels.
A comparison with monarchs of the present century puts Shahjehan in a very favorable light. The wealth of the British Sovereign is estimated at about 170 million dollars. But at a time when the money value was at least six times greater than that of the present era, Shahjehan’s treasury must have held billions of rupees worth of valuables.
The last Nizam of Hyderabad in India, who was a remote descendant of the Moghul dynasty, had treasure and jewelry which it was almost impossible to sell for want of buyers. What can one do with mats oven with priceless pearls and shirts studded with diamonds? He had a paperweight, the famous Jacob diamond, a treasure of 150 carats, the rock-bottom price of which was about 150 lakh rupees.
During the 16th and 17th centuries, India was ruled by the Emperors of the Moghul Dynasty. Of them, six were the most powerful and notable. They were: Babar, Humayun, Akbar, Jehangir, Shahjahan and Aurangzeb. With the death of the last Emperor, the dynasty began disintegrating.
It was during the reign of the last three Emperors that the wealth of the Moghuls was at its peak. Historians have been unable as yet to determine exactly how much the Moghul treasure was worth as some of it was looted by subsequent rulers of India.
Fortunately, Emperor Jehangir has left an authoritative account of his treasure and the list still exists. There was bullion in his treasury amounting to seven tons of gold, and 1116 tons of silver. Among precious stones, there were 80 pounds (more than 5,000,000 carats) of uncut diamonds, 100 pounds each of rubies and emeralds, and 600 pounds of pearls. “Of the other less important varieties of precious stones, the quantity is infinite,” says the document.
The royal armory included 2000 swords studded with diamond-encrusted handles, and the court furniture included 103 chairs of solid silver and five of solid gold. For high dignitaries and visiting monarchs, there were better seating arrangements. Five gorgeous thrones, two of gold and three of silver, were set apart for such persons. Emperor Jehangir himself had seven diamond-studded thrones besides the famous Peacock Throne.
Jehangir’s bathtub today, would be worth the ransom of a billionaire. It was seven feet by five feet in dimensions and was decorated with diamonds to relieve the drabness of gold.
His son Shahjehan, the fifth Moghul Emperor who built the world famous Taj Mahal at Agra was a great connoisseur himself. It was said of him that there was no jeweler in the East who could value precious stones better than he could and the emperor had all luck in pursuing his hobby. He had the first choice of the world’s richest diamond mines, the famous Goldconda fields, and only his rejections were allowed to circulate in the market.
Incidentally, until 1726 AD, the major sources of diamonds in the world were the Golconda mines in India. The Pitt, the Regent, and the Kohinoor are a few of the historic diamonds that owe their origin to Golconda.
Sir Thomas Roe, the British Ambassador to Emperor Shahjehan’s Court, knew to his cost that there could no trifling with the Emperor. Sir Thomas had something like the mythical Unicorn’s horn to palm off. Knowing Shahjehan’s weakness for rare treasure, Sir Thomas tried some sales talk with the Emperor saying that he was offering the horn to him only because the Emperor was the person to appreciate its value.
The horn was supposed to have the rare property of neutralizing any poisonous liquid and as such was considered to be a very welcome gift to sovereigns like Shahjehan, whose life was always in constant danger from enemies. He had hoped this would induce the Emperor to pass it at a high price.
But the shrewd Emperor knew that the horn was not worth the price quoted. He merely thanked the Ambassador and dropped the subject with a courteous expression. The diplomat had to find some other gullible purchaser, and finally, it was disposed of at a cheap price to a Dutch captain.
Shahjehan was no hoarder and often gave away fabulous gems as outright gifts. One day, a diamond brighter than the Pole Star came to his hands from the Golconda mines and the bulwark of Islam as Shahjehan like to call himself, decided that this would be a worthy gift to the Prophet’s Mosque at Mecca. He immediately ordered that a gold candelabra weighing 14 pounds be selected, embellished it with the brighter than the Pole Star diamond, and had it sent post-haste to Mecca. Today, a conservative value of the gift would be about ten million rupees.
Imperial wars also brought treasures to the royal jewel box. When the Moghul forces invaded his domain during the early part of Shahjehan’s reign, the King of Golconda found it advisable to make a peace offering. He sent 200 caskets of jewels to placate the Emperor. But the unfortunate King did not escape his fate. With avarice kindled at the gift, Shahjehan ordered his troops to advance, and they returned with booty exceeding 300 million rupees in value.
No historian could make a correct estimate of Shahjehan’s wealth of which it was said that it was greater than that of his nearest rivals, the Emperors of France and Persia, put together.
But then, there had to be a place to keep all his booty. One fine morning, the Emperor was told by the Master of the Treasury that it was choking with jewels, and that something had to be done to the strong room to relieve the congestion. The Emperor mused for a while. The problem was finally solved by the creation of the famous Peacock Throne. In the late 17th century when it was made, the Throne was valued at an amount equivalent to 530 million rupees. The Throne was completed after seven years of unceasing labor by the Emperor’s best craftsmen.
The plate and cutlery of Shahjehan’s palace weighed 25 tons of gold and 50 tons of silver, respectively. The mere gold content of the plate would today be worth more than 15 million rupees.
In one of his tributes to Shahjehan, Sir Thomas Roe has remarked that the King of Bijapur sent to the Emperor 36 elephants, two of which were adorned with gold chains weighing 400 pounds. There were 50 horses in the gift with trappings worth five million rupees. All possible care was taken that the precious stones were properly graded according to the exacting imperial specifications. For example, the diamonds were divided into 12 categories while pearls were of 16 varying grades.
The draperies of the palace were valued at ten million rupees, and the furnishings include chinaware to the value of 2,500,000 rupees. All the porcelain was imported from China under a special order from the Emperor and was among the best in the era.
The Moghul Emperors were so particular about chinaware that once when a high-ranking officer of the imperial household broke a matching piece of porcelain dish, Emperor Aurangazeb behaved as roughly as an ordinary housewife. He was on a tour of his domains in South India when the hapless official dropped the fruit dish in the capital, Delhi, about 1000 and odd miles away from the Emperor. The culprit knew full well that his carelessness would bring a halter round his neck and at once dispatched a messenger to China to bring back a similar dish to complete the set. He had hoped that the dish would reach Delhi before the Emperor returned from his tour. Unfortunately for him, the Emperor returned far ahead of the schedule, and in course of time, wanted his favorite fruit dish. The trembling official related the accident, and in view of the fact that arrangements had already been made to get a replacement, the official was temporarily excused and suspended pending arrival of the caravan from China.
But the notorious Central Asian robbers made short work of the messengers and the money they carried for purchase of the chinaware. When the period of grace elapsed and there was no news from China, the irate Emperor gave the official the choice between immediate execution and that of going to China to get the porcelain dish.
The official chose the latter course and began the hazardous journey to Cathay (China). As his whole family was held as hostages by the Emperor, he had to be particularly careful about his life and chose the safe route through the Pamir mountains, the so-called backbone of the world. The ranges of the Pamir tower to a height of about 23000 feet and one can very well imagine the plight of the official. Fortunately, Heaven took pity on him and the story of this official reached the court of the then Persian Emperor. This monarch ordered his Grand Wazier to look in the royal Persian cupboards to find whether there was any porcelain dish to match the one for which the official was searching. Happily, such a piece was found, and the Persian Emperor ordered that a gift of this porcelain dish be made to the official. But the poor man was so much broken down in health from the rigors of the journey that he died en route by the time deliverance came.
Emperor Shahjehan did not keep all his treasures in one place. They were divided in varying proportions and were kept in fortresses in different parts of the empire. There were seven of these treasure forts, besides the capital of Delhi. They were Gwalior, Marwar, Lahore, Rantambher, Asirgarh, Rohstsagar, and of course, Agra. The Lahore fort contained the maximum quantity of bullion, while Agra, as the Emperor’s favorite citadel, held most of the jewels.
A comparison with monarchs of the present century puts Shahjehan in a very favorable light. The wealth of the British Sovereign is estimated at about 170 million dollars. But at a time when the money value was at least six times greater than that of the present era, Shahjehan’s treasury must have held billions of rupees worth of valuables.
The last Nizam of Hyderabad in India, who was a remote descendant of the Moghul dynasty, had treasure and jewelry which it was almost impossible to sell for want of buyers. What can one do with mats oven with priceless pearls and shirts studded with diamonds? He had a paperweight, the famous Jacob diamond, a treasure of 150 carats, the rock-bottom price of which was about 150 lakh rupees.
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