(via The Journal of Gemmology, Vol.13, No.1, January 1972) C J Robb writes:
The freshwater pearl of the bivalve unio margaritifera, the animated gem, the ‘na seod’ in Gaelic, was found in the crystal clear meandering rivers of Ireland from the mists of history. It was the prized jewel of the ancient queens, princesses, and fair ladies of those distant times and the hierarchy of the Church regarded it as a token of respect. Bishop Gillbertus of Limerick, gave the Archbishop of Canterbury, St. Anselm, a pearl as a token of his respect in 1094.
Con O’Neill, Prince of Ulster in 1493, bestowed pearls ‘of riches’ on ladies. In 1656 the river Slaney in Co. Wexford was prolific, says Richards, an English writer, in fine pearls of fair luster, magnitude, and rotundity, not inferior to Oriental gems at prices from 20s, to 40s, to the silversmiths and jewelers of London. Sir Robert Reading described pearls from the rivers of Co. Tyrone to the Royal Society in 1688. These gems were mostly of a pale brownish color, some with a greenish tinge. Some of these of good quality weighing up to 36 carats were valued up to £40. A miller found a pearl in the mill race, which he sold for £4 10s and the buyer sold it to Lady Glenawley for which she refused an offer of £80 from the Duchess of Ormond. The Bann River, at Banbridge in Co. Down, was rich in these pearls and a small industry was established to collect, polish and sell them to the best buyers in Dublin, London and Paris. Queen Charlotte had a necklace of Bann pearls valued at £700, one of 4 carats being valued at £60. The river pearls of Ireland had thus an abiding place in the annals of gemology.
Monday, July 02, 2007
Promoting And Merchandising Colored Stones
2007: It's really inspiring, to read Jacques Sabbagh's views on how to sell colored stones. He wrote/addressed this nearly three decades ago, and the truth is his concept still works today. You can still deal with the same sophisiticated, well-informed consumers the old fashioned way.
(via Journal of Gemmology, Vol.XVII, No.3, July 1980) Jacques Sabbagh writes:
It is a privilege for me to address you this evening on the subject of promoting and merchandising colored gems, and it would be a pleasure indeed if I am permitted to do so in an informal way. By your leave I shall start, if I may, on a rather personal note. People who happen to know about the story of my life, seventeen years of which were devoted to medical studies and to the practice of medicine, often ask me with astonishment, ‘How come you changed horses midstream? What made you quit this most noble, this most essential profession, to get involved in the business of colored gems?’— these and similar transparent questions thus implying that my present activity in the jewelry trade is a comparatively futile one and colored gems are rather superfluous commodities. Well, not only do I immensely enjoy my present occupation, but also I happen to be very proud of it. Indeed, I do not believe that jewels are superfluous commodities. I am convinced that they satisfy one of the basic needs and that jewelers cater for one of the fundamental requirement of human nature.
As Thomas Caryle, the 19th century Scots essayist and historian said: ‘The first spiritual want of barbarous man is decoration.’ By this he meant self-adornment, and this is an anthropological fact, substantiated by our observation of the behavior of primitive man of aboriginal tribes still inhabiting certain recesses of the jungle and isolated areas of our planet, as well as by various archaeological findings. Caveman, primitive man invariably demonstrates a tendency for self-adornment by using any handy object that lends itself to this purpose. At the same time, he would attribute occult powers to articles he uses for personal decoration, whether they be perishable items such as bird feathers or plant seeds, or non-perishable objects, as for instance sea shells, animal teeth and claws, or mineral crystals. He would pierce them and then string them and wear them for their often inextricably ambivalent functions: the supernatural power of talismans and charms and the beautifying property of jewelry. In actual fact, excluding the other members of the genus Homo, none of the components of the animal kingdom, even the higher primates, the anthropoid apes, our closest evolutionary ancestors and collateral relatives, exhibit any marked sign of beauty appreciation. It seems that the emergence of a sense of aesthetics, sufficiently compelling to induce artificial additions to the anatomy of even sometimes minor surgical alternations of it, has occurred more or less parallel to the development of language, tools and culture.
Now, with your permission, I would like to venture a diagnosis. Jewelry enterprises that neglect the field of colored gems, that to various degrees discard them from their inventory, are—forgive me for saying so—colorblind. The same way an individual affected by Daltonism, that is colorblindness, misses out on a lot of the beauty, of the glory, of the colorfulness of life and nature around him, seeing them as it were, in different shades of black and white as though he were watching a telecast on the screen of a non-color television set, or a black and white movie picture, a jewelry concern that persists in ignoring the field of colored gems is missing out in incalculable opportunities for profit-making.
Let me sketch out for you a very familiar sequence. When a young woman is considering buying her first piece of jewelry she will, as you know, seek the jeweler almost invariably for a diamond ring. The reason for this is twofold:
1. Diamond, the King of the gem world, is the most prestigious thing to wear, and
2. Diamonds, like pearls, can be used quite indifferently with practically any dress color or style.
Later on, as and when affluence brings its mixed blessings into her life, this young lady will again look up the jeweler for, probably, a diamond brooch or pendant. Sometime later, she may consider changing her ring for a large and more important diamond. To cut a not very long story short, she may eventually look for a pair of diamond earrings; and here it will very likely come to an end, the point of saturation being reached.
On the other hand, once this very same lady develops a sophisticated taste for colored gems, something which requires a certain gratifying dexterousness, some degree of selectiveness in seasonal as well as color matching of jewel and dress—once she starts buying and using them, this new sequence will never end. Her desire for colored gems will prove quite insatiable, due to the enormous variety and the practically endless combinations. The point of saturation in this case is unreachable, it is elusive, unattainable. To put it in a nutshell, colored gems constitute a dimension that extends far beyond the dimension of diamonds. We can have only one monarch: Diamond. The number of princes and barons on the other hand is theoretically unlimited; consequently, colored gems offer, literally, a golden opportunity to the jeweler.
Now, we have to face this question: How can the individual jeweler get into the field of colored gems, or if he is already handling colored gems as a sideline, or even as a main line, how can he develop this branch to its maximum potentiality? In answer to this question, three factors have to be considered. These are:
1. The inventory
2. The point of sale merchandising
3. The sales techniques
Promoting And Merchandising Colored Stones (continued)
(via Journal of Gemmology, Vol.XVII, No.3, July 1980) Jacques Sabbagh writes:
It is a privilege for me to address you this evening on the subject of promoting and merchandising colored gems, and it would be a pleasure indeed if I am permitted to do so in an informal way. By your leave I shall start, if I may, on a rather personal note. People who happen to know about the story of my life, seventeen years of which were devoted to medical studies and to the practice of medicine, often ask me with astonishment, ‘How come you changed horses midstream? What made you quit this most noble, this most essential profession, to get involved in the business of colored gems?’— these and similar transparent questions thus implying that my present activity in the jewelry trade is a comparatively futile one and colored gems are rather superfluous commodities. Well, not only do I immensely enjoy my present occupation, but also I happen to be very proud of it. Indeed, I do not believe that jewels are superfluous commodities. I am convinced that they satisfy one of the basic needs and that jewelers cater for one of the fundamental requirement of human nature.
As Thomas Caryle, the 19th century Scots essayist and historian said: ‘The first spiritual want of barbarous man is decoration.’ By this he meant self-adornment, and this is an anthropological fact, substantiated by our observation of the behavior of primitive man of aboriginal tribes still inhabiting certain recesses of the jungle and isolated areas of our planet, as well as by various archaeological findings. Caveman, primitive man invariably demonstrates a tendency for self-adornment by using any handy object that lends itself to this purpose. At the same time, he would attribute occult powers to articles he uses for personal decoration, whether they be perishable items such as bird feathers or plant seeds, or non-perishable objects, as for instance sea shells, animal teeth and claws, or mineral crystals. He would pierce them and then string them and wear them for their often inextricably ambivalent functions: the supernatural power of talismans and charms and the beautifying property of jewelry. In actual fact, excluding the other members of the genus Homo, none of the components of the animal kingdom, even the higher primates, the anthropoid apes, our closest evolutionary ancestors and collateral relatives, exhibit any marked sign of beauty appreciation. It seems that the emergence of a sense of aesthetics, sufficiently compelling to induce artificial additions to the anatomy of even sometimes minor surgical alternations of it, has occurred more or less parallel to the development of language, tools and culture.
Now, with your permission, I would like to venture a diagnosis. Jewelry enterprises that neglect the field of colored gems, that to various degrees discard them from their inventory, are—forgive me for saying so—colorblind. The same way an individual affected by Daltonism, that is colorblindness, misses out on a lot of the beauty, of the glory, of the colorfulness of life and nature around him, seeing them as it were, in different shades of black and white as though he were watching a telecast on the screen of a non-color television set, or a black and white movie picture, a jewelry concern that persists in ignoring the field of colored gems is missing out in incalculable opportunities for profit-making.
Let me sketch out for you a very familiar sequence. When a young woman is considering buying her first piece of jewelry she will, as you know, seek the jeweler almost invariably for a diamond ring. The reason for this is twofold:
1. Diamond, the King of the gem world, is the most prestigious thing to wear, and
2. Diamonds, like pearls, can be used quite indifferently with practically any dress color or style.
Later on, as and when affluence brings its mixed blessings into her life, this young lady will again look up the jeweler for, probably, a diamond brooch or pendant. Sometime later, she may consider changing her ring for a large and more important diamond. To cut a not very long story short, she may eventually look for a pair of diamond earrings; and here it will very likely come to an end, the point of saturation being reached.
On the other hand, once this very same lady develops a sophisticated taste for colored gems, something which requires a certain gratifying dexterousness, some degree of selectiveness in seasonal as well as color matching of jewel and dress—once she starts buying and using them, this new sequence will never end. Her desire for colored gems will prove quite insatiable, due to the enormous variety and the practically endless combinations. The point of saturation in this case is unreachable, it is elusive, unattainable. To put it in a nutshell, colored gems constitute a dimension that extends far beyond the dimension of diamonds. We can have only one monarch: Diamond. The number of princes and barons on the other hand is theoretically unlimited; consequently, colored gems offer, literally, a golden opportunity to the jeweler.
Now, we have to face this question: How can the individual jeweler get into the field of colored gems, or if he is already handling colored gems as a sideline, or even as a main line, how can he develop this branch to its maximum potentiality? In answer to this question, three factors have to be considered. These are:
1. The inventory
2. The point of sale merchandising
3. The sales techniques
Promoting And Merchandising Colored Stones (continued)
Sunday, July 01, 2007
The Beauty Of Inclusions
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.
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.
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.
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