Dolomite
Dolomite and magnesite – Spain
General
Category	Carbonate mineral
Chemical formula	(CaMg)(CO3)2
Strunz classification	05.AB.10
Crystal symmetry	Trigonal rhombohedral, 3
Unit cell	a = 4.8012(1) Å, c = 16.002 Å; Z = 3
Identification
Color	White, gray to pink
Crystal habit	Tabular crystals, often with curved faces, also columnar, stalactitic, granular, massive.
Crystal system	Trigonal
Twinning	Common as simple contact twins
Cleavage	Perfect on {1011}, rhombohedral cleavage
Fracture	Conchoidal
Tenacity	Brittle
Mohs scale hardness	3.5 to 4
Luster	Vitreous to pearly
Streak	White
Specific gravity	2.84–2.86
Optical properties	Uniaxial (-)
Refractive index	nω = 1.679–1.681 nε = 1.500
Birefringence	δ = 0.179–0.181
Solubility	Poorly soluble in dilute HCl unless powdered.
Other characteristics	May fluoresce white to pink under UV; triboluminescent.
References	[1][2][3][4]

Dolomite ( /ˈdɒləmaɪt/) is a carbonate mineral composed of calcium magnesium carbonate CaMg(CO₃)₂. The term is also used to describe the sedimentary carbonate rock dolostone.

Dolostone (dolomite rock) is composed predominantly of the mineral dolomite with a stoichiometric ratio of 50% or greater content of magnesium replacing calcium, often as a result of diagenesis. Limestone that is partially replaced by dolomite is referred to as dolomitic limestone, or in old U.S. geologic literature as magnesian limestone. Dolomite was first described in 1791 as a rock by the French naturalist and geologist, Déodat Gratet de Dolomieu (1750–1801) from exposures in what are now known as the Dolomite Alps of northern Italy.

Uses[link]

Dolomite with chalcopyrite from the Tri-state district, Cherokee County, Kansas (size: 11.4×7.2×4.6 cm)

Dolomite is used as an ornamental stone, a concrete aggregate, a source of magnesium oxide and in the Pidgeon process for the production of magnesium. It is an important petroleum reservoir rock, and serves as the host rock for large strata-bound Mississippi Valley-Type (MVT) ore deposits of base metals such as lead, zinc, and copper. Where calcite limestone is uncommon or too costly, dolomite is sometimes used in its place as a flux for the smelting of iron and steel. Large quantities of processed dolomite are used in the production of float glass.

In horticulture, dolomite and dolomitic limestone are added to soils and soilless potting mixes to lower their acidity and as a magnesium source. Home and container gardening are common examples of this use.

Dolomite is also used as the substrate in marine (saltwater) aquariums to help buffer changes in pH of the water.

Particle physics researchers prefer to build particle detectors under layers of dolomite to enable the detectors to detect the highest possible number of exotic particles. Because dolomite contains relatively minor quantities of radioactive materials, it can insulate against interference from cosmic rays without adding to background radiation levels.^[5]

See also[link]

Wikimedia Commons has media related to: Dolomite

• List of minerals
• Evaporite

References[link]