Demantoid Garnet, Ural Mountains, Russia

Due to its high refractive index and equally high dispersion, the chromium bearing variety of andradite garnet (named after the Brazilian mineralogist J.G. de Andrada de Silva), was called “diamante”, the Flemish word for diamond, hence the derivation of its present name demantoid. Found only as small crystals in the Ural Mountains of Russia, the premier world locality, gems over a carat in size are uncommon. The color can range from a dark yellow green to the rich, deep green of this stone, the result of chromium. Faceted demantoid garnets frequently contain characteristic radiating needle inclusions that are termed “horsetails” which are inclusions of byssolite. With a perfect shade of green neither too dark nor too yellowish this gemstone is cut in a classic circular brilliant style, and is indeed a rare and exceptional garnet for those born in January.
Weighing 2.55 carats and measuring 8.2 x 4.5mm

Date de cette photo : 1 mai 2008 - 19:25
Envoyé par : Alain Truong
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