Imitation Jewelry Market Update

Gold boom boosts Pak imitation jewellery trade
http://www.commodityonline.com/news/Gold-boom-boosts-Pak-imitation-jewellery-trade-15337-3-1.html

Pakistan’s jewelry-crazy women will definitely add more luster to the imitation jewelry trade as gold prices keeping rising in an amorphous way.

Hematine

Hematite is simulated by a variety of materials. One of these, known as hematine, is a mixture of stainless steel with sulphides of Chromium (Cr) and Nickel (Ni). It has a red streak but is also magnetic, whereas hematite is not.

Victoria Stone

Victoria stone is a complex silicate glass, highly chatoyant due to network of fibers. It's made by melting various minerals + produced in wide color range + perceived as an imitation to many colored stones.

Rough Diamond Imitations In The Market

According to lab gemologists, natural (quartz/phenakite/topaz) or man-made colorless to near-colorless (glass/syn. cubic zirconia/YAG/GGG/strontium titanate/lithium niobate) rough gem materials have been found in natural diamond parcels in the marketplace to confuse the unwary + if in doubt always consult a reputed gem testing laboratory.

Lab Alert!
http://www.gemlab.net/website/gemlab/fileadmin/user_upload/Research/Gemlab-Newsletter-04-2008-forPDF.pdf

Useful link:
www.gemlab.net

For Consumers

The Jewelers Vigilance Committee (JVC) has developed a new consumer brochure to help shoppers understand the difference between natural diamonds + laboratory-created diamonds + simulated diamonds + I think its educational and useful.

Useful links:
www.jvclegal.org
www.moissanite.com

European Jewelry: Eighteenth And Nineteenth Centuries

(via 5000 Years of Gems and Jewelry) Frances Rogers and Alice Beard writes:

4. Engraved Gems, Real And Imitation

Early in the eighteenth century some attempt had been made to excavate the long-buried city of Herculaneum, and later Pompeii. General interest was aroused in the classic forms of art unearthed in these ancient cities. Artists and archeologists flocked to Naples, and fashion took note. Not suddenly but by degrees did the classic influence touch one art after another.

In jewelry the effect was to increase the demand for engraved gemstones, cameos in particular. Immediately there followed a flood of imitation ‘antiques’.

Among those who experimented with making imitation gems was Henry Quinn, a physician, whose name might not have been remembered if it had not been for his young laboratory assistant, James Tassie (1735-99).

The two invented a new form of vitreous paste with which to reproduce ancient gems and medallions, not by copying the engraving by hand, but by casting wax models of the gems.

Tassie became so skillful that his imitations possessed to a high degree the color, transparency and beauty of the originals. His work attracted much attention and he was given access to the finest private collections of ancient gems in Europe in order that he might study and reproduce them. His own collection of reproduction became famous.

At the command of Catherine, Empress of Russia, Tassie made for her copies of all his pastes, a matter of several thousand specimens.

Many of Tassie’s copies eventually became treasured museum pieces. However, to a certain extent it seems to have bene unfortunate for the trade in genuine gems that the copies were so good. Numbers of them fell into the hands of unscrupulous dealers, who passed them off as real, and the too often duped public presently became suspicious of all engraved gems and fearing to find itself deceived, ceased to buy.

More familiar and well known, even down to our times, is the name of the English potter, Joshiah Wedgwood (1730-95). Besides his famous jasperware in classic style, he made cameos for jewelry. Mounted in rings, brooches, or bracelets, his little cameos in delicately tinted jasperware, partcularly in blue and white, became exceedingly popular.

European Jewelry: Eighteenth And Nineteenth Centuries (continued)

Beryl Triplets Imitating Natural Emeralds

It's amazing to see beryl triplets in the gem + jewelry market despite information about the imitation (s) via trade journals/ gemological books/ seminars/ workshops by experts from around the world. The victims include jewelers, gemologists, gem traders + the public.

A beryl triplet is a deception. It has no value. It consists of a crown of colorless beryl (goshenite) or any clean, very light colored beryl (pale aquamarine), and a pavilion of the same material cemented together with a green chromium-based cement. The purpose of the goshenite material is to have the refractive index and specific gravity values in the range of beryl. The green layer of cement is reflected throughout the stone by the facets so that the face-up color of these imitations show good emerald-green color.

Immersion in a suitable liquid will easily show the three parts of the triplet. With some practice + proper magnification (loupe + microscope) one should be able to see the separation plane.

Cobalt-bearing Glass Imitations

Cobalt-bearing glass imitations are still appearing in the gem market in all shapes, sizes and color shades to imitate mainstream colored stones. Watch out for these imitations in Southeast Asia + South Asia + East Africa + alluvial sources. The specimens may have the look and character of the real stones.

Usually 'momentary autism' does the trick because you think you have the right stone + you are in a hurry; you are stitched!

The Emerald Story

Emerald Simulants (synthetics and imitations)

Synthetic emeralds: Synthetic emeralds are man-made emeralds which have the same physical, chemical and optical properties of a natural emerald. Man has very skillfully duplicated this natural green stone so that it is sometimes extremely difficult to tell the difference. However, with the aid of magnification and other tests, a synthetic readily reveals its true identity. Synthetic emeralds have been in the market for several decades, but it’s only now, due to sophisticated mass production techniques that they have become more prevalent and a cause for concern. In the past synthetics were deceptively passed off as natural emeralds by dealers, but today they are now being successfully marketed as synthetics or lab-created by such companies as the San Francisco-based Chatham Inc, Russian-based Tairus, and others.

The techniques employed for the production of synthetic emeralds are:
- Flux growth
- Hydrothermal growth

Flux method: A flux is a chemical compound which when melted has the ability to assist another substance to melt at a temperature lower than would be normal for that material. The chemical components of emerald may be dissolved with an appropriate flux while being held within a platinum-lined crucible. Upon cooling, crystals of synthetic emerald are formed. Chatham employs the flux method for the production of his synthetic emeralds.

Typical inclusions:
- Solid masses of residual flux which appear cloudy.
- Wispy veils—look like thin veils blowing in breeze. Resemble natural liquid fingerprints, but may be more dense.
- Venetian-blind—refers to the appearance of very fine straight line growth zoning which takes on the appearance of venetian blinds.

Hydrothermal process: Of all the synthetic gem growth techniques, this process mimics most closely the process of nature for the creation of emeralds. As the name indicates, it involves water, heat and pressure. Nutrient material (chemical compound for emerald) is placed in an autoclave or ‘bomb’ along with a number of seed crystals located towards to upper (eventually cooler) part of the vessel. Heated water under high pressure dissolves the nutrient and through convection, the chemical needed to grow emerald are deposited on the seed crystal. These crystals now continue to grow so long as the conditions for growth remain and there is a supply of the nutrient.

Typical inclusions:
- Liquid feather with the appearance of fingerprints.
- Distinct fine line zoning.
- Arrow head zoning.
- Nail-head-like phenakite inclusions.

Emerald Story (continued)

Treated And False Stones

(via Roman Book On Precious Stones: 1950) Sydney H Ball writes:

In Pliny’s time, stones were treated to improve their appearance and the art of making paste imitations of gems advanced.

To paraphrase him: All precious stones are improved in brilliancy by being boiled in honey, Corsican honey in particular; acrid substances, however, are injurious to them. (If by ‘boiled’ Pliny means heated, he had the secret of artificially coloring agate; if not, his informants were holding out an essential step in the process). Such treated stones, to which man has imparted new colors, are called physis (‘nature’ or ‘works of nature’), a bit of deception, since dealers recognize that products of nature are more sought after than those of man.

The above free rendering may be a rather obscure reference to an art, which the Hindus even then doubtless practiced, of improving the color of varieties of the cryptocrystalline quartz species by exposure to the sun or to fire, after permitting the more porous layers to absorb honey or other liquids. It is, therefore, believed that the Romans knew something of agate staining. Barbosa (1517 A.D) describes the art and it doubtless long antedated his time. Could the line in Propertius (flourished 30 to 15 B.C) regarding murrha (agate in part) ‘And murrhine vessels baked in Partian hearths’ refer to this process?

The ceraunia, on the other hand, is temporarily improved by being treated for some time in a mixture of vinegar and nitre, and the brilliancy of poor garnets is heightened by steeping for fourteen days in vinegar, the improvement lasting an equal number of months.

Pliny states that books exist which tell how to counterfeit precious stones, but he ‘refuses to name’ the authors, evidently to protect the owners of real gems. This reminds one of David Jeffries’ lament (1750 A.D) when the brilliant cut was supplanting the rose cut diamond, that, provided the ‘fad’ continued, the nobility of England, being large possessors of rose cut diamonds, could be ruined. An earlier analogue is that of the Chinese ambassador, Kan Ying, who reached Antioch, the capital of Rome Syria, in 97 A.D. ‘The articles made of rare precious stones produced in this country are sham curiosities and mostly not genuine, whence they are not (here) mentioned’. Regarding gem counterfeiting, Pliny adds that there is no deceit practiced, which is more profitable. He recognizes that the best method of testing a false stone is to break off a fragment and test its hardness, but the Roman jeweler would not permit this nor the use of the file. In other words, Pliny recognized that hardness is one of the best gemological tests.

As happens today, less valuable stones were palmed off for the more valuable species, and Pliny states, as is the case today, this is a particularly difficult deception for the layman to detect. Sardonyx was imitated by a triplet of a black, a white, and a red stone, each of excellent quality, cemented together. Martian (40-104 A.D), in describing a fine jewelry shop of his day, mentions ‘real sardonyx, indicating that false exists. In Pliny’s time, crystal was stained to imitate emerald and other transparent stones, and other frauds were perpetrated. The people of India, by coloring crystal, imitated various precious stones, particularly beryls. Perhaps the process by which Democritus imitated emerald resembled that of Indian crystal imposition. He discovered, Seneca says, how a pebble can be transformed into an emerald by boiling it. By a similar process artificial gems are stained today. From the Hindu poem Hitopedesa (dating from about the time of Christ), we quote the following lines, more or less detached, to be sure:

‘Silly glass in splendid settings, something of the gold may gain;
And in company of wise ones, fools to wisdom may attain.’
‘Glass will glitter like the ruby, drilled with dust—are they the same?’

An ancient Hindu play Mrichchhakatika or Little Clay Cart (6th century A.D?), as to Hindu makers of false stones, says ‘they readily fabricate imitations of ornaments they have once seen, in such a manner that the difference shall scarcely be discernible’.

Returning to Pliny, he says that any color can be imparted to amber that may be desired, it being sometimes stained with kid suet and root of orchanet; indeed, in his day, amber was even dyed purple. Much amber was used, he says, to counterfeit gems, especially amethyst. We may add that today pressed amber is successfully colored.

The artisans of Pliny’s time imitated many stones in glass and some of these false gems which have come down to us would test the skill of an expert of today. Certain Italian jewelers still, after recutting, sell as real gems the pastes dug up in Rome. Obsidian, murrha, crystal, and other stones were imitated. Pliny states that glass imitations of jasper are easily detected and as to opal, it is the most perfectly imitated, although the opalescence is partly or largely lacking. The callaina (turquoise) is also successfully counterfeited. Genuine capnias is much colder than the glass imitations. Carbunculus (garnet and other red gems) is well counterfeited, but the glass imitation is softer, comparatively brittle and lighter in weight. Further, the inclusions differ. The Egyptian cyanos is undoubtedly a blue frit, an imitation of turquoise.

The Egyptians and the citizens of Ur made glass imitations of gems some 5000 years ago. Later (1600-1400 B.C) the Myceneans were adept at the trade. On the other hand, while there are a few Greek paste intaglios of the 4th century B.C, such were rare before the 3rd century B.C. Pastes were much used in Rome until some years after Pliny’s time, when they became less common, probably because genuine precious stones were in large supply. Glass in Pliny’s time furnished the poor, who could afford gems, not only with the ‘costume’ jewelry of that day, but with a necessary signet. Paste in those days was, from its decorative value, ranked nearer to precious stones than it is today, for the faceting of stones, which brings out the full beauty of the transparent gems, was then in its infancy. Further, in those days, glass was a much more scarce and precious substance than it is today, so that its use in jewelry was less culpable than today. Alexander Severus, in attempting to stamp out the luxury of Heliogabalus’ reign, placed heavy taxes on the glassmakers. Diocletian (Emperor, 284-305 A.D) decreed that all books describing the synthesis of gold and silver and the fabrication of artificial precious stones should be burned.

There is a thought-provoking statement in Horace, namely, crystal vases ‘had been spoiled by an admixture of glass’. The Romans, in the writer’s opinion, could scarcely have melted rock crystal and glass together.

I think we can all smile with Emperor Gallienus, who reigned from 260 to 268 A.D. A jeweler had sold Gallienus’s wife, the Empress Salonina, false gems for true. She called the matter to the attention of the emperor and he immediately ordered the jeweler to be thrown to the wild beasts in the circus. Naked, the poor wretch stood in the arena awaiting his doom. The door of the wild beasts’ den was thrown open; out strutted a rooster! The emperor’s comment, ‘he who had cheated others should be cheated himself.’ More militant punishment is recommended in the Hindu Agastimata (16th century), as follows: ‘The vile man who fabricates false diamonds will sink into an awful hell, charged with a crime equal to murder.’

One of the last parts of Book XXXVII is an excellent and, to all intents and purposes, a modern summary of the methods of testing gems. This has already been quoted in the section on Pliny as a mineralogist. In short, glass imitations are lighter, better conductors of heat, contain more gas inclusions, and are softer than gemstones.

Tortoise Shell vs. Imitations

For thousands of years Tortoise shell has been associated with jewelry and personal items such as combs, eyeglass frames and art objects. They were popular with both the ancient Greeks and wealthy Romans. Many types of tortoise shell objects have been used for furniture inlays, eyeglass frames, decorative boxes, rings, bracelets, and earrings. In Japan, tortoise shell crafting or bekko, has been an important industry since at least the 17th century, centered in Nagasaki. Bekko objects such as hair ornaments are still being created today from stockpiled material. The source material comes from two species of sea turtles: the hawksbill and the rare green turtle. The shell tend to show attractive patterns from light to dark brown patches and other desirable shades. The popularity of tortoise shell from 18th through 20th century caused these animals almost to extinction leading to a near-worldwide ban in the 1970s + international trade in tortoise shell products.

Common imitations include plastic, phenol formaldehyde resin (bakelite), polyester resins (PET and polyurethane) among many others. Sometimes the identification could be a challenge for various reasons. For instance plastics and horn can imitate blond tortoise shell quite easily and the differences in luminescence may not be always diagnostic. Plastic (s) could be altered via change (s) in its chemical compositions, polymerization or the applications of dyes. Identifications may not be always that easy. Since tortoise shell and their imitations are fashioned into ornamental materials, standard tests beyond UV luminescence and hotpoint may not always be possible. It’s catch-22. According to experts, Tortoise shell and its imitations can be identified with standard (microscope, refractive index, specific gravity, UV fluorescence, etc) + analytical (photoluminescence spectroscopy, transmission infrared spectroscopy, specular reflectance infrared spectroscope, vis-nir spectroscope, raman spectroscopy), gemological tests.

Specialty Glasses

Aventurine Glass is man-made paste with the addition of fine copper spangles. The reddish brown variety is sometimes met with under the name gold stone or gold star stone. Spangled-aventurine-effect is due to triangular or hexagonal scales of copper. The blue variety (lapis imitation) is colored by cobalt and will appear red under the Chelsea Color Filter.

Slocum Stone is a recent (1976) opal imitation named after its Canadian inventor. It is a composite paste, probably consisting of a body of crown glass of low R.I. (about 1.52) and melting point, into which are pressed fragments of thin films of blown glass of differing R.I. Colors are probably due to interference between layers of differing R.I. The diagnostic features are flow lines and bubbles distorted by pressure during manufacture. Slocum stone triplets are now on the market as well. Slocum stone has been marketed under the deceptive name 'Opal Essence'. Slocum stone can be an extraordinarily good opal simulant. It is reported that the results of production can vary from batch to batch. Some stones display pinfire-type play of color; others may show much broader triangular flashes of color. The background may be black, translucent or nearly completely transparent like fine crystal opal. Low power magnification under the gemological microscope will reveal the twisted tinsel-like nature of the color flashes.

Rhinestone refers to transparent paste which, colorless in the main, shows patches of various colors. Most specimens consist of a thin metallic film which has been vacuum-sputtered onto the surface of the glass thereby causing iridescence.

Imori Glass or Meta Jade is a partially devitrified, translucent green glass produced by Imori in Japan. Slow cooling cause partial crystallization, which often appears as a dendritic (fern-like or tree-like) structure under magnification. The stones may show gas bubbles.

In some cases asterism is obtained by engraving fine, intersecting lines, or by impressing three sets of intersecting lines, on the back of a cabochon. The stones then are frequently backed by colored foil to lend color and increase reflectivity. On the other hand, cat's-eye-like effects can be obtained by the incorporation of parallel glass fibers or by the elongation of included bubbles.

Imperial Topaz Imitation

Natural deep yellow orange pink variety of topaz (imperial topaz) is rare and expensive. The important source for this gem is Ouro Preto, Minas Gerais, Brazil. For now there are no known synthetic imperial topaz, but common imitations such as synthetic spinel, citrine, spessartite garnet and glass are common at the source as well in the international colored stone markets. But lately more synthetic imperial topaz-like corundum (Verneuil/Flame Fusion), rough/cut are seen + for the unsuspecting buyer this could become a problem stone. Standard gemological tests will easily separate common imitations, but the intruders can be a problem when you have to deal with hundreds of stones in a parcel.

Ruby / Sapphire Fakes

When you are visiting gem mines or markets in Africa, South Asia, South East Asia, South America and North America, you might encounter the following stones. Gem dealers, jewelers and gemologist (s) may or may not be able to recognize the 'intruders' or 'tell-tale' signs of the fakes due to 'momentary autism', lack of knowledge or even over confidence.

I.
- Heat treated, tumbled Verneuil synthetic ruby
- Heat treated and/or ‘quench-crackled’, tumbled Verneuil synthetic ruby.
- Heat treated and/or ‘quench-crackled’, tumbled, oiled or waxed Verneuil synthetic ruby.
- Heat treated and/or ‘quench-crackled’, blue dye impregnated, tumbled Verneuil synthetic ruby.
- Heat treated tumbled Verneuil synthetic ruby with fillings + with/without colored wax.
- Heat treated, tumbled Verneuil synthetic filled with fused particles of blue sapphire.
- Heat treated, tumbled Verneuil synthetic ruby that has modified opening (s) filled with fused particles of blue sapphire.
- Natural pink sapphires rough coated with dark red nail polish.

***** May Look Like Natural Ruby Rough

II.
- Heat treated, fashioned, tumbled Verneuil synthetic ruby.
- Heat treated, fashioned, tumbled, partly blue painted Verneuil synthetic ruby.
- Heat treated and/or ‘quench-crackled’, fashioned, tumbled Verneuil synthetic ruby.
- A composite crystal containing fragments of Verneuil synthetic ruby.

***** May Look Like Ruby Crystals

III.
- Heat treated and/or ‘quench-crackled’ Verneuil synthetic ruby.

***** May Look Like Faceted Ruby

IV.
- Heat treated and/or ‘quench-crackled’ Verneuil synthetic sapphire.

***** May Look Like Faceted Sapphire

Aqua Aura

(via Wikipedia) Aqua Aura is a term used to describe a natural crystal that has been coated with gold fumes. It is created in a vacuum chamber from quartz crystals and gold vapor. The quartz is heated to 1600 degrees Fahrenheit in a vacuum, and then gold vapor is added to the chamber. The gold atoms fuse to the crystal's surface, which gives the crystal an iridescent metallic sheen. The process was awarded the United States Patent No. 6997014 on Feb 14, 2006. The process was invented by Steven F. Starcke, Ronald H. Kearnes and Keven E. Bennet. While the patent might have been given in 2006, this material has been produced by this method for dozens of years prior.

The patent says "The invention provides a decorative object comprising a transparent or translucent substrate having a body and at least one surface bearing a thin film coating. The coating imparts in the substrate a body color that appears substantially constant at different angles of observation. This body color is imparted in the substrate at least in part by absorption of visible radiation that is transmitted through said coating. The coating includes a high absorption layer comprising film that is highly absorptive of visible radiation. Also provided are methods of coating gems and other decorative objects, as well as methods of heat treating coated gems and other decorative objects."

Aqua Aura is a very popular item in metaphysical items and a popular item in jewellery. It is the exact same process that is used to coat steel balls used as bearings. The term Aqua aura specifically is used for the blue colored quartz. Additional elements can be used to treat quartz, such as indium, titanium and copper. The coloring of this treatment is only on the surface, so all faceted and polished material you find has been treated after it has been made originally. Often, quartz of lesser quality, with fractures and weak spots, will break apart during the coating process.

A little known fact is that the Aqua aura treatment can be used to reveal twinning in quartz crystals that would otherwise go undetected. While most all treated quartz is destined for the metaphysical marketplace, it does have a use in the field of mineralogy. (http://en.wikipedia.org/wiki/Aqua_aura)

Aqua Aura treated quartz or topaz could be visually confused for heat treated zircons because the prominent iridescence in treated specimens may be confused for dispersion. Standard gemological tests such as refractive index, birefringence and specific gravity should easily identify the stones. Also cobalt-doped blue synthetic quartz may look very similar to Aqua Aura treated stones. In this case Chelsea color filter reaction and absorption spectrum should easily provide diagnostic results; as the synthetic quartz will show pink through the Chelsea color filter + cobalt absorption spectrum. Aqua Aura treated topaz may be confused for irradiated blue topaz. In the case of quartz and topaz the unnatural iridescence is the indicator + magnification. The absence of pleochroism is also another indicator. Another interested aspect is when you study the treated quartz + topaz under proper magnification you may notice dark color concentrations of color along facet junctions + the uneven coloration very similar to blue diffusion-treated sapphires. Buyer beware!

Some Aspects Of Fraud

2007: With the spread of gemology you think most if not all of these tricks should never succeed, but to tell you the truth, today, it does. Synthetic, treated, and imitation gemstones have just become too sophisticated (there are many) + gem testing laboratories are in dilema describing what they see, especially with treatments (nearly all colored stones are treated one way or the other), because they need the trade as well as the consumers to function as a business + gem dealers and jewelers have no time/patience sitting with gem testing instruments to identity/sell their merchandise, because the pereception is if you think like a gemologist you won't be able to buy/sell colored stones, so they leave it to the trade/independant laboratories + the so-called experts for their opinion, and this is where opinions may go right/wrong/misinterpreted + the well-trained fraudsters are also familiar with gemology, treatments, synthetics and imitations + its limitations so they become adept playing their game.

(via The Journal of Gemmology, No.1, Vol.1, January 1947) Robert Webster writes:

Value is an essential concomitant of that type of criminal offence which the legal mind terms ‘stealing by false pretences’ and the jeweler trading in precious stones is a fitting target for this type of trickery. The following notes, based on factual reports and personal experiences, may make interesting and informative reading, and may in some measure prevent others suffering loss through the same pitfalls. Although all the episodes mentioned may not have been fraudulently conceived, most would have, or had, the stricture of the law upon them.

Perhaps it would be wise to remark that no trick of this nature would be effective unless some preparation in the way of the gaining of confidence were first engendered. To walk into a shop, place a four carat zircon on the counter and say ‘I want £700 for this diamond’ would not get a rogue very far with hard-headed businessman of today; but with confidence established suspicion is lulled and almost anything may happen. Indeed, it can be given as an axiom that one is never caught except when haste is the ‘jade’ a ‘breezy’ type of personality or pretty face and a trim figure be the distraction, or when the desire for profit overcomes commonsense.

It is fitting that the diamond be the first stone to consider, for that is the gem most handled by the jeweler and the most likely to be the stone whose simulation leads to chicanery. The substitution of a diamond by a paste imitation does not, at first sight, appear a likely cause of loss, for only an imitation jeweler would come to grief with this fake; it is the amateur who falls for a piece of glass. What member of the trade has not heard of the wonderful bargain bought in a public house for a song? Inevitably it is the jeweler who has the unenviable task of supplying the denouement.

Most jewelers have encountered false diamonds which they glibly term ‘jargoons’ ‘doublets’ or ‘white sapphires’, often totally unaware of the correct interpretation of the names they use. In most of these cases the fake has been the colorless zircon which owes its lack of color to heat treatment and has a high dispersion. Exhibited in a ‘half light’, such stones do show an appreciable resemblance to diamond—providing one does not look for the strong double refraction. Time and time again these zircons have caught the unwary, often the same operator working the same fraud for months on end until Nemesis finally overtakes him.

The diamond doublet, although so often mentioned, does not appear to be so prevalent as is generally supposed. Of three authentic cases known to the writer, one consisted of a crown of true diamonds and a base of glass; in another the base was probably rock crystal; the third, a stone with a two carat spread and mounted with ‘roman’ or ‘gipsy’ setting in a heavy gold ring, caused the jeweler who bought the ring (as dusk, when the light was bad) to lose many pounds. This stone, which the leaders of the jewelry trade considered to be such a dangerous fake that they instituted a ‘broadcast’ caution, was found to have a base of synthetic white spinel.

It is doubtful whether the synthetic white sapphire has ever caused much difficulty, but mention must be made of the artificially produced colorless spinel, if only to comment on the journalistic enthusiasm which caused the ‘diamond scare’ of 1935. These ‘Jourado diamonds’ generally ‘emerald cut’, a style which was then beginning to be favored for diamonds, did momentarily cause confusion, but only for the few hours before the report of the Laboratory Experts was published by press and radio. That these synthetic white spinels have not been entirely neglected by the unscrupulous is recalled by the recent conviction of the Dutchman, Winnser, but this probably more in the nature of substitution than in direct simulation.

Comparatively early in the writer’s career he met with the ‘painted’ diamond. Shown a single stone diamond ring which had been pledged by a gentleman prominent in the theatrical profession, he noticed something ‘not quite right’ about the stone, but lack of experience precluded a definite reason. The opinion of an experienced diamond broker confirmed this suspicion; he washed the stone in hot water, thereby removing the dye from the rear facets, and returned an off-colored yellowish diamond instead of the ‘white’ stone submitted to him. The method used to restore the stone to a white color need not be considered here.

It is questionable whether the inducing of a green color in a diamond by radium emanations, so easily detected by autophotography and spinthariscopic observation, can be called fraudulent, for in the case of the heat treatment of zircons and topazes and the staining of agate, the alteration of hue is not considered to be wrong providing the stone is sold as such; but how often is the radium-treated diamond so sold?

Although having little application to the retail jeweler, the imitation of diamond crystals goes to show to what length the crook fraternity will go in their endeavor to make money by fraud. There have been three authentic cases of ‘diamond octahedra’ which had been found to have been artificially shaped from base material. In two of these cases the material used was synthetic colorless corundum, and for the third case colorless quartz was used.

Most jewelers, knowing all too well the synthetic production of the corundum gems, ruby and sapphire, are wary of dealing with such stones unless they have sound reasons or are backed by a laboratory report, and it is rare that loss is occasioned by such an artifice. That fraud can occur, even with an experienced trader, was made apparent recently when a three-stone ruby ring was bought for some hundred of pounds, it being discovered later that the most important center stone was synthetic.

With respect to emerald, the most likely cause of trouble is surely the composite stone better known as the soude’ emerald, but despite the undoubted fine effect of this counterfeit, the writer cannot recall a single case of fraud involving this stone. The true synthetic emerald which is now being made in America has as yet not invaded this country, and when it does, as surely it will, more care still will be required by the members of our trade.

The painting of the rear facets of pale rubies, sapphires and emeralds in order to enhance their color is too patent and too well known to cause much difficulty, and the same may be said for the older type of garnet-topped doublets. The imitation of the alexandrite by the synthetic version of corundum and spinel does not now appear to worry the trade as it has done in the past, nor, for that matter, do the opal doublets; on the other hand, the orange red synthetic corundum, sometimes called the ‘padparadshca’ is still confused with the fire opal by some people less informed than their neighbors.

Before bringing these few notes to a close, reference must be made to gem pearl, for although the cultured pearl is so well known and so difficult in some cases to detect at sight, that risk is rarely taken. It is with the black pearl that trouble may occur, for artificial coloration may be particularly good, and, rather surprisingly, that hoary textbook fake, the polished hematite sphere, has quite recently shown itself. What probably was the most unusual fake that the writer came across was a necklace of pink beads, bought as coral, which turned out to be vegetable ivory appropriately stained.

With the spread of the science of gemology, most, if not all of these tricks should never succeed, and those enemies of society who perpetuate them be forever put out their nefarious business—but for the frailty of human nature.

Tanzanite And Some Imitations

Zoisite: Blue to violet
Tanzanite (trade name)
R.I=1.688 – 1.696 (1.691 – 1.700); Birefringence=0.008 – 0.009; S.G=3.35

Heavy Pb-Glass
U.M Tanzanic (trade name)
R.I=1.600 – 1.605; Birefringence= Isotropic (SR); S.G=3.36 – 3.48

YAG
Purple Coranite (trade name)
R.I= >1.80; Birefringence= Isotropic (SR); S.G=4.58

Synthetic Corundum
Blue Coranite (trade name)
R.I=1.764 – 1.771; Birefringence= 0.007; S.G=4.02

YAG
Russian YAG (trade name)
R.I=>1.80; Birefringence= Isotropic (SR); S.G= 4.56

Ca-Phosphate Glass
R.I=1.537; Birefringence=Isotropic (SR); S.G=2.64

Synthetic Or Artificial

2007: Even today many don't know/understand the difference (s) between synthetic and artificial gemstones. The minute you mention synthetic they will ask if it's glass or plastic; to my surprise even gemologists, jewelers and traders ask the same. I call it momentary autism. They go blank/inert. I think gemological education should be perceived as a life long learning endeavor.

(via The Journal of Gemmology, Vol.VII, No.6, April, 1960) A E Farn writes:

Most gem enthusiasts have at some time or other either attended a gemological exhibition, or proudly shown their own collection of gems to friends and relations—always to be asked the inevitable question, ‘how much are they worth?’ To the keen collector, this is an irritating question, since it indicates clearly where the interest lies and how the average person reacts to such terms as gemstones or jewelry. Seldom does one meet the true appreciation of beauty or rarity, but always the eternal ‘how much?’

Unfortunately certain elements in our society readily apply their criminal psychology to this materialistic interest in valuables so quickly evinced by the more greedy or gullible section of the public. Thus, when a new material came on to the market and displayed tremendous fire and attraction for a price low in comparison to diamond it afforded possibilities which the unscrupulous were not slow to realize. The new material’s trade name of fabulite seemed coined specially for word play—fabulous for the credulous! It was not until some fairly recent occasion that I was asked by a gem dealer, who wanted to satisfy a customer’s enquiry, whether it was intended to simulate diamond and if it was a synthetic stone.

Answering rather quickly without very serious thought, I replied that it certainly was not intended to simulate diamond but doubtless it could be so used. It was not synthetic diamond, since its formula was SrTiO3, strontium titanate, but it could be described as a synthetic stone. Since then I have had second thoughts. I began to wonder if it was correct to describe this product as synthetic, and without going into the various aspects and methods of manufacture of synthetics generally I wondered whether it was correct so to describe strontium titanate.

Being weak on etymology I could only have recourse to what I had been taught, and as far as I could remember a synthetic stone is a stone which has the same chemical composition, refractive indices and specific gravity as its natural counterpart.

If a synthetic ruby be analyzed it would correspond with natural ruby and similarly in the case of sapphire. With synthetic spinel this is not quite the same, as here there is an excess of alumina in the composition and the properties are slightly higher in R.I and S.G than those of natural spinel. It would seem to be hair-splitting, but even synthetic spinel is not a true synthesis of natural spinel. It did not intend to propound this particular case, but it slipped in as a natural sequence.

What I really wanted to focus on is: strontium titanate, is it a synthetic, since so far as is known there is no naturally occurring mineral? Certainly it is an artifact as indeed are all synthetics, whether corundum, spinel, rutile or emerald. The Concise Oxford dictionary gives synthesis as ‘combination, composition, putting together. Chemically: artificial production of compounds from their constituents.’ Jarrold’s dictionary of difficult words gives synthesis as ‘combination of parts into a uniform whole. Synthetic—pertaining to synthesis and adjectivally as artificial.’ Webster’s Compendium carefully states, ‘synthetic gems having similar chemical composition to natural corundum and spinel and which in physical and optical properties approximate to these gems are made in an oxy-coal gas furnace (Verneuil process)’. Anderson’s Gem Testing gives: ‘synthetic stones, manufactured stones which have essentially the same composition, crystal structure and properties as the natural mineral they represent.’

It would seem, therefore, that a consensus of opinion is against terming an artifact of no known natural counterpart as a synthetic from a gemological view. Incidentally, most so called synthetics which have a counterpart in nature are all certainly harder than fabulite, which has a softness too low to admit of normal jewelry usage. It would seem therefore that strontium titanate is in fact an artificial stone and should be so described.

Beryl Triplets Imitating Paraiba Tourmaline

Top and bottom pieces of near colorless beryl fused together and colored by a layer of blue green glue is perceived as good imitation for Paraiba/Paraibla-like tourmaline.

A Further Note On Diamonds, Real And Imitation, In The Roman Period

(via The Journal of Gemmology, Vol.13, No.8, October 1973) J M Ogden writes:

Since the brief note on Roman imitation diamonds by the writer was published in the Journal of Gemmology two fine Roman rings, both set with interesting stones have been available for study. The first has an attractive openwork-sided setting in which is set an octahedral stone. This stone was at first glance taken to a rock crystal of the type considered by the writer to be a Roman imitation of a natural diamond crystal. Closer inspection of the stone however revealed the typical surface decomposition characteristics of glass and the stone was, in fact, a yellowish white glass (the term paste would be wrong here, as technically this should only refer to those glasses with high refractive index and brilliance). The writer knows of other instances of rings set with glass octahedral, and these, like the rock crystals, might be taken to be imitations of diamond crystals. It might be argued that any reasonably knowledgeable Roman could have told glass from the invincible diamond, but one would expect that these copies of diamond crystals were more in the nature of moral frauds; in other words they would have been worn by those to whom the diamond was, for reasons of economy or rank out of reach. A similar state of affairs can be seen earlier in the Roman period when only free-born citizens were allowed to wear gold rings; slaves and others made do with wearing gilt bronze rings.

The second ring is extremely interesting and possibly even unique, as it is set with a brown diamond. This stone, larger than any other Roman diamond known to the writer, is in the form of rough natural twin octahedral. Alec Farn of the Gem Testing Laboratory very kindly examined and tested this stone and found it to be a brown-series diamond: two lines, at 4980 Angstrom, were visible in the spectrum, and there was a blue fluorescence under X-rays. The weight of the stone was difficult to gauge, but it must have been about 7 carats. The majority of the Roman diamonds known to the writer do not have recorded weights, but they generally would seem to weigh under a carat. This large stone under discussion was by no means obviously a diamond from color or appearance, except to one versed in crystallography; so other stones of a similar nature might exist, unrecognized, in museum or private collections. In its recent history the stone in this ring has been described in a multitude of ways, most recently as ‘Topaz’. This fine ring is of a similar type to the first ring mentioned above, although it is sturdier and its size would indicate that it was definitely a man’s ring. Both these rings were originally in the collection of Count Henri de Clercq Boisgelin, a well-known collector whose ancient jewelry included some of the finest specimens known. There is no cause to doubt that both these rings are genuine, and that they date from the late Roman period (c. 3rd - 4th century A.D). Close examination by the writer revealed no evidence that the stones were not originals: indeed the ring holding the diamond had quite obviously been made for that stone and none other. The coloration, surface appearance under strong magnification and the general ‘feel’ of the gold in both cases would show that the settings were as old as supposed.

No provenance is recorded for either of these rings, though it would seem likely that they were made in Italy or in one of the Eastern Roman centers such as Asia Minor or Egypt. The exact area of origin for the diamond is not known, but it would be likely that it was traded ‘loose’ from India, possibly via Alexandria.