Stephanite
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 3.0)
Mineral NameStephanite
Chemical FormulaAg₅SbS₄
Mohs Hardness2
Crystal Systemorthorhombic
Lustermetallic
Streak Colorblack
Cleavagedistinct on {010}
Fractureconchoidal
Specific Gravity6.2
Colorsiron-black, lead-gray
Transparencyopaque
Type LocalityGrube Gnade Gottes, St Andreasberg, Revier St Andreasberg, Harz, Lower Saxony, Germany
Mineral GroupSulfosalts
Usesore of silver, collector
Associated Mineralspyrargyrite, native silver, galena, sphalerite, chalcopyrite, quartz, calcite
Rarityuncommon
Description
This specimen features dark, metallic, platy to tabular crystals of stephanite embedded in a matrix, with small reddish crystals of pyrargyrite also visible.
Geological Context
Stephanite typically forms in low-temperature hydrothermal veins, often found in association with other silver-bearing minerals in epithermal deposits.
