Clausthalite
ID: 37
Clausthalite
Chemical Formula
PbSe
Hardness (Mohs)
2.5 - 3
Crystal System
Isometric
Streak
Gray to black
Luster
Metallic
Diaphaneity
Opaque
Color
Lead-gray to tin-white
Crystal Habit / Mode of Occurrence
Isometric - Hexoctahedral; commonly granular, massive, or compact; rarely distinct cubic crystals.
Fun Facts
Clausthalite is the lead analogue of galena, meaning it has the same crystal structure as galena but with selenium substituting for sulfur. Common Uses: Minor ore of selenium; collector's mineral.