Coloradoite, calaverite and gold from Kalgoorlie, Australia — Photo: Kritzolina · CC BY-SA 4.0
Coloradoite
Mercury telluride — a rare telluride ore associated with gold-silver deposits.
Intro adapted from Wikipedia (CC BY-SA).
Coloradoite is an IMA-recognized mineral species in the sulfide class, with the chemical formula HgTe.
It crystallizes in the cubic crystal system (space group F-43m). It is a member of the Sphalerite structural group.
Key properties: Mohs hardness 2.5; specific gravity 8.1; gray-black streak; Bright metallic. Anisotropism: Moderate, dark brownish red to blue-gray. R: (400) 33.8, (420) 35.4, (440) 36.5 luster.
IMA symbol Clr, grandfathered status — known before the IMA’s founding, named in 1878.
Found in hydrothermal tellurium-bearing precious metal veins.
It is found associated with Altaite, calaverite, krennerite, petzite, gold, pyrite, chalcopyrite, sphalerite, galena, pyrrhotite, tetrahedrite–tennantite.
The name refers to the Keystone and Mountain Lion mines, Magnolia, Magnolia district, and Smuggler mine, Ballerat district, Boulder Co., type localities in Colorado, USA.