Chalcocite
ID: 61
Chalcocite
Chemical Formula
Cu₂S
Hardness (Mohs)
2.5 - 3
Crystal System
Monoclinic
Streak
Blackish lead gray
Luster
Metallic, Sub-Metallic
Diaphaneity
Opaque
Color
Blue black, gray, black, black gray, or steel gray
Density
5.5 - 5.8
Fun Facts
Named chalcosine in 1832 by François Sulpice Beudant from Greek, "chalkos", copper. This mineral was known by a wide variety of names previously. In 1868, James D. Dana and George J. Brush renamed this material "chalcocite". Tenacity: Brittle.