crystals of garnet var. uvarovite : Saranovskii Mine (Saranovskoe), Saranovskaya (Sarany) Village, Gornoazavodskii area, Permskaya Oblast’, Middle Urals, Urals — Photo: Parent Géry · Public domain
Uvarovite
The emerald-green chromium garnet — the rarest common garnet, always small-crystalled.
Intro adapted from Wikipedia (CC BY-SA).
Uvarovite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₃Cr₂(SiO₄)₃.
It crystallizes in the cubic crystal system (space group Ia3d). It is a member of the Garnet structural group.
Key properties: Mohs hardness 6.5–7.5; specific gravity 3.77–3.81; typically green; White streak; Vitreous luster; refractive index 1.865; optically isotropic.
IMA symbol Uv, IMA status: approved, named in 1832.
From hydrothermal alteration of serpentinite containing chromite; in metamorphosed limestones and skarns from the reaction of dolomite and chromite.
It is found associated with Chromite, diopside, zoisite, olivine, dolomite, tremolite, quartz, plagioclase, epidote, calcite, chromian clinochlore, pyroxenes.
The name refers to Count Sergei Semenovich Uvarov (1786–1855), Russian nobleman, President of Academy of Sciences.
Collections: Gemstones, Collector Favorites, Rare & Remarkable.