Krennerite

krennerite, a gold mineral that usually occurs in veins formed at low temperatures, as at Kalgoorlie, Australia, and Cripple Creek, Colo., U.S. A gold telluride (AuTe₂), it forms orthorhombic crystals. Two chemically similar minerals, calaverite and sylvanite, form monoclinic crystals; they are more common than krennerite, are important primary ores of gold, and are sources of tellurium. All three substances have similar chemical and physical properties. For detailed physical properties, see sulfide mineral (table).