Photo of Unarovite in Processed & Rough Form
Unarovite is a mineral with a hardness of 8 out of 10 on the Mohs scale of mineral hardness [?]. These Cubicly structured gems are made of iron aluminum silicate, their full chemical compound being Ca3Cr2(SiO4)3.
Uvarovite is a rare, calcium-chromium emerald-green variety of Garnet. Together with grossular (calcium-aluminum) and andradite (calcium-iron), it makes up the series of ugrandite garnets. These three have similar crystal structure and form, but just have different chemical proportions.
It occurs in mixed crystals, so there is a partial replacement of some elements by others. It stands out from this mix as a beautiful, intense, deep emerald green. Fine pieces feature a sparkling, bright-green surface of small crystals that cover the rock thickly, evenly and smoothly. Large crystals are significantly darker.
It is very hard, heavy, fragile, and has no cleavage. Its crystals are transparent with a luster just a little less than that of diamond. It has a relatively high melting point and is insoluble in acids.
Its color is due to its chrome content, which is responsible for both the red of rubies, spinel, pyrope, and pink topaz; and also the green color of emerald, jade, alexandrite, jade, demantoid, and some tourmaline.
Uvarovite occurs in serpentine rocks rich in chromite. It is found in serpentinites, in igneous rocks with a high content of olivine, pyroxenes, etc., and other chromium-bearing rocks; also in skarns (metamorphic rocks consisting of calcium, magnesium, and iron silicates).
This rare mineral has been found among the chrome deposits of Syssertsk, in the Urals (Russia); in the Bushveld, Transvaal, (South Africa); and in the Kop Krom mine, Erzerum (Turkey). In Italy it has been found in Val Malenco (Sondrio), and at St. Marcel in Val d'Aosta. In Quebec, (Canada), California (USA)Fine specimens of well-formed uvarovite crystals come from Outukumpu, Finland.
Other names for uvarovite are chrome garnet, chromium garnet, and green garnet.
Luoshiliushi is a Chinese term for green uvarovite used as jade.
It is alternatively spelled as uwarowite or ouvarovite.
Uvarovite is often confused with emerald.
Because of the solid solution between uvarovite and grossular many green garnets are mistakenly termed 'uvarovites' when they are really chromian grossular.
The specific gravity [?] for Unarovite is 3.77, its refractive index [?] is 1.86-1.87, and its double refraction [?] is None.
History
Uvarovite was named after the Russian statesman Count Sergei Semenovitch Uvarov.
Industrial Usages
Uvarovite is used as a gemstone, but its commercial use is limited because it is so rare. It is rarely cut as cabochon or faceted as a gem, but it is prized by collectors.
It is seldom found in gem crystals of cuttable size, but in tiny proportions. The overall appearance of rock matrix specimens is so attractive, so thin-shaped pieces for setting in jewellery are made where much of the supporting matrix is cut away leaving a thick pile of medium-grain, bright-green vitreous uvarovite crystal covering from edge to edge.
You May Also Like...
Euclase: Euclase is a silicate with a monoclinic crystal system. It is considered a very rare gem of light blue color. It appears as long or short prismatic crystals, flattened and transparent. It is colorless, white, green, or blue, commonly a pale aquamarine or green, but crystals of a very fine dark blue (from iron) have been found at the Miami mine in Zimbabwe. Crystals are often striated. It (read full)
Petalite: Petalite is a lithium aluminum silicate that is an important ore of lithium. This mineral forms, rarely, as small crystals, which are commonly twinned. More often, petalite forms as large, cleavable masses. It may be white, grey, pinkish, yellow, or colorless. It is transparent to translucent, with a vitreous to pearly luster, and fuses with difficulty. It forms in very coarse-grained, acid igne (read full)
Jadeite: Jadeite is a silicate of sodium and aluminum, and is a member of the Clinopyroxene group of minerals. It is so called because it is the source of one of the ornamental materials commonly known as Jade. It has a monoclinic crystal system, and occurs as granular aggregates of small crystals, but has occasionally been found in crystals of a few centimeters. The color varies a great deal because of t (read full)
Peridot: Peridot is the greener type of gem-quality specimen of Forsterite-Olivine, which is an important, rock-forming mineral, a silicate of magnesium and iron. Often their names are used interchangeably. The bottle-green/olive green type of olivine is also called olivine. The yellower type of olivine is called Chrysolite. It forms as thick, tabular crystals, frequently with wedge-shaped terminations. T (read full)
Orthoclase: Orthoclase mineral is a silicate of potassium and aluminum, belonging to the Feldspar group. It has the same composition as microcline, but is stable at slightly higher temperatures. It occurs as prismatic, sometimes flat-sided crystals, but in rocks it is usually anhedral. It may be perfectly transparent and yellow or almost colorless, but it is more often semi-opaque and white to grayish-white, (read full)
