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Roger Weller, geology instructor
Chemical Group: oxide
Chemical Formula: Cu2O
Color: red, nearly black Streak: brownish red
Luster: adamantine to submetallic; may also be earthy
Hardness: 3.5 t0 4
Specific Gravity: 6.10
Fracture: conchoidal Tenacity: brittle
Cleavage: (111) weak
Crystals are usually octahedrons, but may also be cubes or dodecahedrons.
An acicular form (needle-like) is called chalcotrichite.
Mineral Associations: malachite, azurite, tenorite, copper, iron oxides
Identifying Characteristics: softer than hematite, harder than cinnabar
Uses: copper ore
Occurrences: found in oxidized zones of copper deposits
Toxicity: when-swallowed- moderate when inhaled- moderate
Additional Information: Cuprite can be replaced as a malachite pseudomorph.