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Gemstone Encyclopedia
Detailed information for any gemstone you are interested in.
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When you join the IGS community, you get trusted diamond & gemstone information when you need it.
Detailed information for any gemstone you are interested in.
When you join the IGS community, you get trusted diamond & gemstone information when you need it.
Almandine is perhaps the most common garnet species. Forming series wi...
Gem ProfileRare and difficult to cut, anhydrite is seldom faceted. However, this ...
Gem ProfileExtremely rare as a cut gem, even in very complete collections. Many o...
Gem ProfileSeveral species of marine mollusks produce stony growths called calcar...
Gem ProfileProfessionals will tell you never to trust a trade name used to descri...
Gem ProfileOne of the most prized ornamental materials in China, chicken-blood st...
Gem ProfileMarketed as "Gem Silica" this relatively rare, blue to blue-green, opa...
Gem ProfileAny stone that changes color under different types of light is a rare ...
Gem ProfileColor change sapphires are those that change color between light sourc...
Gem ProfileOne of the rarest garnet varieties, demantoid can have a green color t...
Gem ProfileLike their marine cousins, many freshwater mollusks can produce pearls...
Gem ProfileGrossular garnets come in almost every color, even colorless, except b...
Gem ProfileIt should not be difficult to find numerous small faceted huebnerites ...
Gem ProfileHydrogrossular differs from the other garnets in that it is never tran...
Gem ProfileIdocrase is one of the lesser known and more beautiful collector gems....
Gem ProfileMalaia or malaya garnets are typically light to dark, slightly pinkish...
Gem ProfileManganotantalite makes a spectacular red brown gem that is a very rare...
Gem ProfileAll three minerals are fibrous or elongated zeolite minerals. Faceted ...
Gem ProfileNiccolite’s delicate peachy red color and metallic luster looks beauti...
Gem ProfilePadparadscha sapphires show a blend of orange and pink colors, one of ...
Gem ProfileDiscovered in 1989, paraíba tourmalines are among the world’s most pri...
Gem ProfileFibrous pectolite has long been a curiosity for gem collectors. Compac...
Gem ProfileRhodolites are purplish red garnets, a blend between almandine and pyr...
Gem ProfileUsually orange to reddish brown, gem-quality spessartite or spessartin...
Gem ProfileSphene, also known as titanite, has rich body colors, strong trichrois...
Gem ProfileAlthough sulfur is very abundant, facetable material is not. Sulfur is...
Gem ProfileTanzanite has had a rapid rise to prominence among jewelers and gem en...
Gem ProfileTriphylite is one of the world's rarest gems. The IGS had the extraord...
Gem ProfileAn emerald-green variety of grossular garnet, tsavorite is one of the ...
Gem ProfileAlways a dark, rich green color, uvarovite is one of the rarest member...
Gem Profile
