Copper
ID: 24
Copper
Chemical Formula
Cu
Hardness (Mohs)
2.5 - 3
Crystal System
Isometric
Streak
Copper-red
Luster
Metallic
Diaphaneity
Opaque
Color
Copper-red, tarnishes to brown or green (patina)
Crystal Habit / Mode of Occurrence
Isometric - Hexoctahedral; commonly in cubes, octahedra, dodecahedra (often distorted); more typically found as nuggets, wires, arborescent (tree-like) growths, flakes, or massive.
Fun Facts
Native copper deposits can form spectacular masses, some weighing many tons, found in Michigan's Upper Peninsula. Common Uses: Electrical wiring, plumbing, coinage, roofing, statuary, alloys (brass, bronze).