Calcite is chemically speaking calcium carbonate. The mineral literally forms the skeleton of our planet. Mountain systems, the Great Barrier Reef in Australia, as well as such life forms as starfish, hedgehogs, snails or mollusks – they all are composed of calcite.
The stone itself may be generated in the hot springs or in the cold cave streams. It may be also formed in volcanic magma. Ancient people used calcite to build houses carve sculptures, make decor items and jewelry.
The mineral is available in various colour shades – purple, red, blue, brownish, white, black, orange, light pink, green. A distinctive feauture of the mineral is that all the varieties have double refraction of light. It means that objects or images, if looked through the stone, seem to be twice their size.
Calcite deposits are mainly located in the USA, Italy, Greece and Mexico. In Russia, the mineral is extracted in the Urals. Nowadays, calcite is actively used in optics, metallurgy, chemical production and construction industry.
A unique and the most complete collection of calcite is presented in the Museum of the Mining University. To be fair, it is the world’s biggest collection of calcite that is in possession of the Mining University – about a thousand and a half of the mineral’s samples from more than fifteen countries.
The first sample of optical calcite, originating from Iceland, was acquired by the Mining University as a part of the collection purchased from the English trader J. Forster in 1802. The exhibit item is in fact a colorless transparent notch, which is by size 17.5 by 15 centimeters in mineral cleavage.
The Mining Museum also houses minerals from the Hermitage collection of Catherine the Great, which were moved by the Emperor Alexander I in 1816 to the Mining Cadet corps. By now, about five samples of calcite of those times have been identified.
A spherocrystal. Diameter - 120 mm, Nikolaevskoe deposit, Dalnegorsk ore field.
An intergrowth of crystals. Cumberland, England.
Calcite "The Rose". The 1st Soviet mine, Dalnegorsk ore field.
Calcite with fluorite, Cumberland, England
The first sample of optical calcite in the Mining Museum, Iceland.
Calcite from the Hermitage collection of Catherine II, Germany.
Calcite from the Hermitage collection of Catherine II, France.