Chemical Formula: (Au,Ag)Te2
Locality: Sacarâmb (Nagyág, Szekerembe), Transylvania, Romania.
Name Origin: Named for Joseph A. Krenner (1839-1920), Hungarian mineralogist.
Krennerite is an orthorhombic gold telluride mineral which can contain a relatively small amount of silver in the structure. The formula is AuTe2 varying to (Au0.8,Ag0.2)Te2. Both of the chemically similar gold-silver tellurides, calaverite and sylvanite, are in the monoclinic crystal system, whereas krennerite is orthorhombic.
The color varies from silver-white to brass-yellow. It has a specific gravity of 8.53 and a hardness of 2.5. It occurs in high temperature, hydrothermal environments.
Krennerite was discovered in 1878 in Sacaramb, Romania, and first described by the Hungarian mineralogist Joseph Krenner (1839–1920).
Color: White, Blackish yellow.
Fracture: Conchoidal – Uneven – Uneven fracture producing small, conchoidal fragments.
Hardness: 2.5 – Finger Nail
Streak: greenish gray