Coloradoite

Coloradoite
Coloradoite from the La Plata District of Colorado
General
Category	Telluride mineral
Formula (repeating unit)	HgTe
Strunz classification	2.CB.05a
Crystal system	Cubic
Crystal class	Hextetrahedral (43m) H–M Symbol: (4 3m)
Space group	F43m
Unit cell	a = 6.453 Å; Z = 4
Identification
Color	Iron-black inclining to gray
Crystal habit	Massive, granular
Fracture	Uneven to subconchordial
Tenacity	Brittle
Mohs scale hardness	2.5
Luster	Bright metallic
Streak	Black
Diaphaneity	Opaque
Specific gravity	8.10
References

Coloradoite, also known as mercury telluride (HgTe), is a rare telluride ore associated with metallic deposit (especially gold and silver). Gold usually occurs within tellurides, such as coloradoite, as a high-finess native metal.

The quest for mining led to the discovery of telluride ores which were found to be associated with metals. Tellurides are ingrown into ores containing these precious metals and are also responsible for a significant amount these metals being produced. Coloradoite is a member of the coordination subclass of tellurides is a covalent compound that is isostructural with sphalerite (ZnS). Its chemical properties are highly instrumental in distinguishing it from other tellurides. First discovered in Colorado in 1877, other deposits containing coloradoite have been discovered since then. Although it plays an important role in the geology of minerals, it can also be used for other purposes.

Telluride ores occur mainly with metal deposits. In 1848, C.T. Jackson was the first to discover an American mineral containing the element tellurium in the Whitehall mine, in Spotsylvania County, near Fredericksburg, Virginia. Tellurides of gold were first discovered in 1782 in Transylvania and subsequently other telluride ores were found in other parts of the world (Mark and Scibird, 1908). The first discovery and description of coloradoite was by Frederick Augustus Genth in the Boulder veins of Colorado in 1877 and so named after the place of discovery. Other studies have reported its occurrence in other mines of the region and also in mines of the world's significant telluride locations. First classified in the 02 class of minerals by James Dana, its classification number is 02.08.02.05. It is also has a Strunz classification of 02.CB.05a, as a metal sulfide with gold, silver, iron, copper and other metals.