Synthetics, Simulants, & Treatments

Bakelite Pepper Brooch. Photo Courtesy of Bonhams.

Bakelite

Bakelite is a variety of moldable plastic that was invented by Leo Bakeland in 1909. Chemically, it is described as ...
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Pearl Necklace

Bleach

Akoya Pearl Necklace.Akoya pearl bleaching is a common, but generally undisclosed treatment used to even out the color in white cultured pearls ...
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Bone Brooch

Bone

Bones are the rigid skeletal parts that form the framework that supports the bodies of vertebrates. Bone has been used ...
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Boule

Boule

Split Boules of Flame Fusion Corundum.Photo by Morion Company.Boule refers to the rough form of synthetic corundum or spinel, produced through the flame fusion/Verneuil ...
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Vintage Camphor Glass and Diamond Ring.

Camphor Glass

Camphor glass is clear glass that has been treated with hydrofluoric acid vapors to give it a frosted, whitish appearance ...
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Chatham

Chatham

Chatham, as used in gemological conversation, stands for a manufacturing technique of synthetic gemstones. The method incorporates crystallization of a ...
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Opal Doublet/Triplet

Composite Stone

Composite Stone - Triplet. Composite stones are gem simulants that are composed out of several materials. Doublets and triplets are good examples. Composite stones ...
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Pair of Earrings Each with Four [[Coque de Perle]] (Nautilus Shell 'Pearls'); Bordered with Iron Pyrites Set in Silver. 1726-1775 © Trustees of the British Museum.

Coque de Perle

Coque de perle, from the French for 'pearl shell' was a Georgian faux pearl carved from the East Indian nautilus ...
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Paste Used to Imitate Yellow Natural Gemstones in Costume Jewelry.

Costume

Paste Used to Simulate Yellow Natural Gemstones in Costume Jewelry. Costume jewelry is jewelry made from less costly materials such ...
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Round Brilliant-Cut Cubic Zirconia.

Cubic Zirconia

Round Brilliant-Cut Cubic Zirconia. Cubic zirconia is a man-made material used to imitate diamond and other gemstones, commonly referred to as CZ. Cubic ...
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Synthetic Ruby, Czochralski Boule.

Czochralski

Synthetic Ruby, Czochralski Boule. The Czochralski method, developed by Polish scientist Jan Czochralski, was a byproduct of his investigation into ...
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Dyeing

Dyeing

The dyeing or staining of gemstones is one of the oldest gem treatments. Somewhat porous gemstones, such as polycrystalline varieties, allow pigments ...
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Coco Chanel Faux Pearl, Turquoise and Rhinestone Necklace.

Faux

Faux (from French: "false") is the name given to imitation jewelry, in particular to simulated pearls.Coco Chanel Faux Pearl, Turquoise and Rhinestone ...
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Glass Filled Ruby

Filling

Filling is a gemstone enhancement method which indicates a broad range of treatments. From simple oiling to resin impregnation to the filling ...
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A Second Typical Feature of Verneuil Corundum: Clouds of Small Gas Bubbles.

Flame Fusion

Flame fusion, discovered in 1902 by Auguste Verneuil, was the first successful process creating synthetic gemstones. Using powdered elements and high ...
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Foil-Backed Topaz and Chrysoberyl Bracelet.

Foil Backed

Foil backing (or foiling) is a gemstone surface enhancement technique where a thin sheet of metal or other material (sometimes ...
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Pyrite

Fool’s Gold

Fool's gold is the popular name for pyrite. Pyrite looks like gold but is hard and brittle and lacks the malleability of gold. Fool's Gold aka ...
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French Ivory

French Ivory

French ivory is a yellowish-white plastic which imitates ivory ...
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Victorian Mourning Cameo with a Surround of French Jet and Seed Pearls.

French Jet

Victorian Mourning Cameo with a French Jet and Seed Pearl Surround. French jet is a black glass which is used ...
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White Casein Australian Royal Air Force Buttons.

Galalith

Galalith is a milk casein product that resembles bakelite or celluloid. Sometimes erroneously referred to as "French Bakelite," this substance was developed in ...
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Typical, Perfectly Spherical Bubble in Paste Resembling the © Sign. Photo by Tim Spauwen.

Gas Bubble

Gas bubbles are the rounded bubbles seen in glass resulting from trapped gasses during the manufacturing process. It is sometimes necessary to ...
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A Foil Backed Colorless Quartz Cabochon.

Gemstone Surface Enhancements

Surface Enhancements Gemstone surface treatments are techniques that are applied to the surface of gemstones and diamonds in order to enhance ...
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Gadolinium Gallium Garnet aka GGG

GGG

Gadolinium Gallium Garnet. A synthetic gemstone used as an early diamond substitute. GGG is manufactured by the Czochralski method and ...
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Glass

Glass

Most glass is a man-made material sometimes used to simulate a gemstone. In that case, it's called paste. There are also three ...
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Gutta Percha Cameo Pendant.

Gutta-Percha

Gutta-percha is a dark rubbery, organic substance derived from tropical trees (Sapotaceae palaquium). From the mid 1800's it was used ...
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Halo (Stress Fracture) in a Sapphire Indicating Possible Heat Treatment.

Heat Treatment

Introduction Gemstones are colored because certain wavelengths of the visible spectrum of electromagnetic radiation get absorbed while other wavelengths are transmitted. Which ...
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Hornbill Jewelry Suite.

Hornbill Ivory

In the fall of 2009 Stone Group Labs received an unusual item for identification. It turned out to be manufactured ...
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HPHT Diamond Diagram.

HPHT

HPHT treatment stands for high pressure - high-temperature treatment. This method of diamond enhancement, invented in the late 1960's, started to be applied commercially ...
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Vauxhall Paste Ring. Circa 17th Century. Photo Courtesy of the Museum of London.

Imitation

Paste Used to Imitate Yellow Natural Gemstones in Costume Jewelry.An imitation is an object or gemstone which is used to ...
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n 1904 William Crookes, a well known physisist discovers that diamonds turn green upon exposure to radium. (TIm)

Irradiation

In 1904 William Crookes, a well known physicist discovers that diamonds turn green upon exposure to radium. The diamonds stayed radioactive and ...
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Jasperware Cameo.

Jasperware

Jasperware was matte finish pottery product (some refer to it as porcelain) developed by Josiah Wedgwood and used to imitate ...
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Large Scale Synthetic Star Ruby and Platinum Diamond Ring

Laboratory Grown

Gemstones that are produced by man are generally termed "laboratory grown". These can be synthetics or other inorganic minerals that have no ...
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Laser Drilled Diamond.

Laser Drilling

Laser Drilled Diamond. The Drill Channels you See are Not All Individual Channels, for the Most Part, They are Reflections.Image ...
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Mallorca Pearl.

Mallorca Pearls

Majorica is a brand name of a high-quality pearl simulants produced on the Spanish island of Majorica at the Majorica S.A. company ...
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Black Enamel and Marcasite Pendant Watch

Marcasite

Marcasite is an iron sulfide mineral with an orthorhombic crystal structure. It is very brittle and unsuitable for jewelry. What ...
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Mikimoto, Kokichi

Mikimoto, Kokichi

K. Mikimoto 1858-1954 Kokichi Mikimoto was born in Toba, Japan on January 25, 1858. Born of humble beginnings he was ...
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Mounting on Moor

Mounting on Moor

"Mounting on moor" refers to the tinting of diamonds on the pavilion to create a more uniform color and to hide dark ...
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Cedar Oil for Emerald Enhancement - Before and After.

Oiling

Oiling is a gemstone treatment typically used for emerald and other gems with cracks that extend to their surface. Applying oil, with a refractive ...
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Opaline Glass Buttons c.18th Century. ©Victoria & Albert Museum.

Opaline Glass

Opaline glass was a gem imitation with a milky white to blue appearance generally cut en cabochon a popular daytime "gem" in ...
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Antique French Enamel and Paste Silver Gilt Necklace.

Paste

Example of a Paste Sapphire Imitation. Notice the Rounded Facet Edges Which Tell Us the Stone Wasn't Cut, but Cast ...
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Vauxhall Paste Ring. Circa 17th Century. Photo Courtesy of the Museum of London.

Paste Jewelry

Paste jewelry is costume jewelry, mainly set with colored and/or colorless glass. During the eighteenth century with the vogue for faceted gems and diamonds, the demand ...
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Pate de Verre

Paté de verre is a French term which literally means "glass paste". Ground glass, which could be colored by pigments, ...
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Bakelite Multi-Colored Bangle Bracelets and Earclips. Photo Courtesy of Bonhams.

Plastic

Plastics are man-made substances used in jewelry to imitate natural gem materials. Early plastics were organically derived, like the combination ...
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French Antique Silver, Enamel and Paste Necklace

Rhinestone

Rhinestone is the name given to rock crystal which is faceted to imitate diamond. It is also a name for ...
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Strass

Strass

Glass with high lead content. The lead increases the refractive index, specific gravity and dispersion but lowers the hardness. Strass was invented in the 18th century by ...
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Boule

Synthetic Corundum

External Link History of Synthetic Corundum:  http://www.dtic.mil/dtic/tr/fulltext/u2/a460239.pdf Gems & Gemology: The Quarterly Journal of the Gemological Institute of America. Synthetic Corundum: ...
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Synthetic Diamonds In the Lab.

Synthetic Diamond

Video Presentation on Diamond SynthesisGems & Gemology: The Quarterly Journal of the Gemological Institute of America. Synthetic Diamond: March-April 1935, Synthetic ...
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Synthetic Emerald and Diamond Flower Motif Ring

Synthetic Emerald

Synthetic Emerald Created by the Renowned Chatham Company, est.1938, San Francisco. Gems & Gemology: The Quarterly Journal of the Gemological Institute ...
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