This is the green uvarovite cabochon. Dimensions: 0.7 x 0.4 x 0.1″ (1.7 x 0.9 x 0.2cm). Weight – 0.1oz (1 grams). Origin: Russia, Ural.
Some information about uvarovite:
Uvarovite is a chromium-bearing garnet group species with the formula: Ca3Cr2(SiO4)3. It was discovered in 1832 by Germain Henri Hess who named it after Count Sergei Semenovitch Uvarov (1765–1855), a Russian statesman and amateur mineral collector. It is classified in the ugrandite group alongside the other calcium-bearing garnets andradite and grossular.
Uvarovite is the rarest of the common members of the garnet group, and is the only consistently green garnet species, with an emerald-green color. It occurs as well-formed fine-sized crystals.
Uvarovite most commonly occurs in solid solution with grossular or andradite, and is generally found associated with serpentinite, chromite, metamorphic limestones, and skarn ore-bodies.