Mineral Information and Data:

Cu [CNMNC approved formula]

Named from Greek "kyprios", of Cyprus, the location of ancient copper mines; Latin "cuprum".

IMA status : Valid species (Pre-IMA Ancient) Grandfathered
(8th edition) :  
  (01) Native Elements
  (01.01) with metallic elements other than the platinum group
  (01.01.01) Gold group
(10th edition) :
  (01) Elements
  (01.A) Metals and Intermetallic Alloys
  (01.AA) Copper-cupalite family
Crystal system: Cubic System
Point group (H-M): m3m (or 4/m 3 2/m) — hexoctahedral
Unit cell: a = 3.615 Å
Crystal Habit: Crystals cubic, octahedral, dodecahedral, tetrahexahedral; arborescent, wirelike, massive, powdery
Twinning: Common on {111}; contact, penetration, or cyclic
Color: Copper red, brown; pale rose when fresh, pale pink
Diaphaneity: Opaque
Luster: Metallic
Hardness (Mohs): 2.5 to 3
Measured Density: 8.94 g/cm3
Cleavage: None
Tenacity: Highly malleable and ductile
Fracture: Hackly
Streak: Pale red
Geologic Setting: Commonly associated with porous zones in mafic extrusive rocks, less commonly in sandstones and shales, where the copper was probably of hydrothermal origin, precipitated as the result of oxidizing conditions; in the oxidized zone of large, disseminated copper deposits as a result of secondary processes. A rare mineral in some meteorites.
Mineral Association: Silver, chalcocite, bornite, cuprite, malachite, azurite, tenorite, iron oxides, many
other minerals
Synonyms/varieties: Whitneyite (As-rich var.)


Origin: St. Véran, French Alps
Picture size: 33 x 48 mm
Sample owner: W.R. Moorer
Photo: Pieter Stemvers, Leusden, Netherlands


Copper with calcite crystals up to 8 mm
Origin: Quincy Mine, Houghton, Michigan, USA
Sample size: 7 x 5 x 5 cm
Photo: Tom Loomis


(zoom-in of above)