Ourayite Locality: Pitiquito, Sonora, Mexico ( Locality at mindat.org ) A rich thumbnail specimen showing embedded, silvery ourayite (a very rare silver lead bismuth sulfide) on all sides. Ex American Museum of Natural History specimen. 1.9 x 1.7 x 1.7 cm. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Ourayite
Ourayite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Ag₃Pb₄Bi₅S₁₃.
It crystallizes in the orthorhombic crystal system. It is a member of the Lillianite structural group.
Key properties: specific gravity 7.18.
IMA symbol Our, IMA status: approved, named in 1976.
Found in a hydrothermal sulfide vein (Old Lout mine, Colorado, USA); with topaz and fluorite in a cryolite body (Ivigtut, Greenland); with base-metal sulfides in diopside tactite (Pitiquito, Mexico).
It is found associated with Galena, matildite (Old Lout mine, Colorado, USA); berryite, aikinite, galena, matildite, pyrite, bismuth, gold (Ivigtut, Greenland); sphalerite, galena.
The name refers to Ouray, Colorado, USA, near where the mineral was first discovered.