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In 1986, California named benitoite as its state gemstone, a form of the mineral barium titanium silicate that is unique to the Golden State and only found in gem quality in San Benito County. [ 80 ] ^ Colorado is the only state whose geological symbols reflect the national flag's colors: red (rhodochrosite), white (yule marble), and blue ...
The Gemological Institute of America ( GIA) is a nonprofit institute based in Carlsbad, California. It is dedicated to research and education in the field of gemology and the jewelry arts. [ 1] Founded in 1931, GIA's mission is to protect buyers and sellers of gemstones by setting and maintaining the standards used to evaluate gemstone quality.
Gemstones of the World revised 5th edition, 2013 by Walter Schumann ISBN 978-1454909538 Smithsonian Handbook: Gemstones by Cally Hall, 2nd ed. 2002 ISBN 978-0789489852 v
Jewelry applications of precious opal can be somewhat limited by opal's sensitivity to heat due primarily to its relatively high water content and predisposition to scratching. [11] Combined with modern techniques of polishing, a doublet opal can produce a similar effect to Natural black or boulder opal at a fraction of the price.
Jet (gemstone) Jet is a type of lignite, [ 1] the lowest rank of coal, and is a gemstone. Unlike many gemstones, jet is not a mineral, but is rather a mineraloid. [ 2] It is derived from wood that has changed under extreme pressure. The English noun jet derives from the French word for the same material, jaiet (modern French jais ), ultimately ...
Gemstone. Group of precious and semiprecious stones—both uncut and faceted—including ( clockwise from top left) diamond, uncut synthetic sapphire, ruby, uncut emerald, and amethyst crystal cluster. A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or ...
Diamond[ a] is a gemstone formed by cutting a raw diamond. Diamonds are one of the best-known and most sought-after gems, and they have been used as decorative items since ancient times. The hardness of diamond and its high dispersion of light —giving the diamond its characteristic "fire"—make it useful for industrial applications and ...
Jewellery (or jewelry in American English) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a western perspective, the term is restricted to durable ornaments, excluding flowers for example.