Uvarovite is a

chromium Chromium is a chemical element; it has Symbol (chemistry), symbol Cr and atomic number 24. It is the first element in Group 6 element, group 6. It is a steely-grey, Luster (mineralogy), lustrous, hard, and brittle transition metal. Chromium ...

-bearing

garnet Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. Garnet minerals, while sharing similar physical and crystallographic properties, exhibit a wide range of chemical compositions, de ...

group species with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

: Ca₃ Cr₂( Si O₄)₃. It was discovered in 1832 by Germain Henri Hess who named it after Count Sergei Uvarov (1765–1855), a

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

n statesman and amateur mineral collector. It is classified in the ugrandite group alongside the other calcium-bearing garnets

andradite Andradite is a Mineralogy, mineral species of the Garnet, garnet group. It is a Silicate minerals#Nesosilicates, nesosilicate, with chemical formula Ca3Fe2Si3O12. Andradite includes three varieties: * ''Colophonite'': a historical variety found ...

and

grossular Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. The name grossular is derived from ...

. 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.

Occurrence

Uvarovite most commonly occurs in

solid solution A solid solution, a term popularly used for metals, is a homogeneous mixture of two compounds in solid state and having a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. The word "solutio ...

with

, and is generally found associated with

serpentinite Serpentinite is a metamorphic rock composed predominantly of serpentine group minerals formed by serpentinization of mafic or ultramafic rocks. The ancient origin of the name is uncertain; it may be from the similarity of its texture or color ...

chromite Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. It can be represented by the chemical formula of Iron, FeChromium, Cr2Oxygen, O4. It is an oxide mineral belonging to the spinel group. The ...

, metamorphic limestones, and

skarn Skarns or tactites are coarse-grained metamorphic rocks that form by replacement of carbonate-bearing rocks during regional or contact metamorphism and metasomatism. Skarns may form by metamorphic recrystallization of impure carbonate protoliths, ...

ore-bodies. File:garnet.uvarovite.500pix.jpg, Pendant in uvarovite, a rare bright-green garnet. The long dimension is 2 cm (0.8 inch) The most significant source of uvarovite historically has been a now-closed copper mine at Outokumpu, Finland, from where most museum specimens have been collected. The uvarovite crystals found in the Outokumpu district are among a wide range of chromium-rich silicate phases found in association with volcanogenic copper-cobalt-zinc sulfide ore deposits which are known to have an unusually high chromium content. Uvarovite occurrences in the United States are predominantly found in the western portion of the country, including localities in

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, and

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

. In the eastern United States, uvarovite has been confirmed in Lancaster County,

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

. The mineral has also been reported from eastern

Cuba Cuba, officially the Republic of Cuba, is an island country, comprising the island of Cuba (largest island), Isla de la Juventud, and List of islands of Cuba, 4,195 islands, islets and cays surrounding the main island. It is located where the ...

. 9 grains of uvarovite occur in a heavy mineral fraction of bulk stream sediment HM-10 collected in Bunker Hill creek, below the historic Bunker Hill gold mine, south of Nelson in British Columbia Canada. Its source is likely near serpentinites and argillaceous limestones within about 450 m upstream of the silt site. Notable localities in Europe besides the Outokumpu site known to bear uvarovite include Røros, Norway; Pitkyaranta, Russia; Val Malenco, Italy; Pico do Posets near Venasque, Spain; Kip Daglari, Turkey; and Biserk and Sarany, Russia. In Africa, uvarovite has been reported from the

Bushveld Igneous Complex The Bushveld Igneous Complex (BIC) is the largest Layered intrusion, layered igneous intrusion within the Earth's Crust (geology), crust. It has been tilted and Erosion, eroded forming the outcrops around what appears to be the edge of a great Ba ...

of Transvaal,

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and from the Vumba Schist Belt in

Botswana Botswana, officially the Republic of Botswana, is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory part of the Kalahari Desert. It is bordered by South Africa to the sou ...

. In Asia, uvarovite has been reported from

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

. and

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, uvarovite has been reported from chromite deposits in southern

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

Properties

Minerals in the uvarovite-grossular series are stable up to temperatures of 1410 °C at low pressure.

References

External links

{{Commons category, Uvarovite Calcium minerals Chromium minerals Garnet gemstones Minerals described in 1832

Occurrence

Properties

See also

References

External links