Cuprite
ID: 19
Cuprite
Chemical Formula
Cu₂O
Hardness (Mohs)
3.5 - 4
Crystal System
Isometric
Streak
Reddish-brown
Luster
Adamantine to submetallic to earthy
Diaphaneity
Transparent to translucent (in thin pieces) to opaque
Color
Ruby-red, brownish-red, sometimes nearly black.
Crystal Habit / Mode of Occurrence
Isometric - Hexoctahedral; commonly octahedral, dodecahedral, or cubic crystals; also massive, earthy, capillary ("plush copper").
Fun Facts
The beautiful deep red color of cuprite makes it a striking mineral, and well-formed crystals are highly prized by collectors. Common Uses: Minor ore of copper, collector's mineral.