The Collaborative International Dictionary
Tetrahedrite \Tet`ra*he"drite\, n. [So called because the crystals of the species are commonly tetrahedrons.] (Min.) A sulphide of antimony and copper, with small quantities of other metals. It is a very common ore of copper, and some varieties yield a considerable presentage of silver. Called also gray copper ore, fahlore, and panabase.
Wiktionary
n. (context mineralogy English) A complex ore of copper, a mixed sulfide of copper, iron, zinc, silver and antimony.
Wikipedia
Tetrahedrite is a copper antimony sulfosalt mineral with formula: . It is the antimony endmember of the continuous solid solution series with arsenic-bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the two, the antimony rich phase is more common. Other elements also substitute in the structure, most notably iron and zinc, along with less common silver, mercury and lead. Bismuth also substitutes for the antimony site and bismuthian tetrahedrite or annivite is a recognized variety. The related, silver dominant, mineral species freibergite, although rare, is notable in that it can contain up to 18% silver. Tetrahedrite gets its name from the distinctive tetrahedron shaped cubic crystals. The mineral usually occurs in massive form, it is a steel gray to black metallic mineral with Mohs hardness of 3.5 to 4 and specific gravity of 4.6 to 5.2.
It occurs in low to moderate temperature hydrothermal veins and in some contact metamorphic deposits. It is a minor ore of copper and associated metals. It was first described in 1845 for occurrences in Freiberg, Saxony, Germany.
Usage examples of "tetrahedrite".
These creatures wandered the Great Escarpment in loose caravans, seeking the diffuse surface areas of stratiform copper deposits, preferably those with high amounts of tetrahedrite or chalcocite in them, so that they could recover silver as a byproduct of the copper.