Calaverite
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameCalaverite
Chemical FormulaAuTe₂
Mohs Hardness2.5
Crystal Systemmonoclinic
Lustermetallic
Streak Colorgreenish-gray to yellowish-gray
Cleavagedistinct on {201} and {110}
Fractureuneven
Specific Gravity9.1
Colorssilvery white, brassy yellow, dull yellow, brown
Transparencyopaque
Type LocalityCripple Creek, Cripple Creek District, Teller County, Colorado, USA
Mineral GroupTellurides
Usesore of gold, collector
Associated Mineralssylvanite, krennerite, petzite, native gold, quartz, pyrite
Rarityuncommon
Description
The image displays a cluster of elongated, metallic, brassy-yellow Calaverite crystals, some showing a slightly tarnished surface. The crystals are well-formed and exhibit a distinct metallic sheen.
Geological Context
Calaverite typically forms in low-temperature hydrothermal veins, often associated with volcanic or subvolcanic environments where gold and tellurium-rich fluids circulate. It is a primary ore mineral for gold in such deposits.
