Cuprite

Properties

Chemical Composition: 

Oxide of Copper - Cu₂O

Classification / Type: 

-

Colors / Varieties: 

Dark purplish red to brownish red to nearly black with a metallic appearance.

Crystal System / Forms: 

Cubic System<

Hardness: 

4

Specific Gravity: 

5.85 - 6.15

Cleavage / Fracture: 

Poor, indistinct / Uneven fracture

Optic Character: 

Isotropic

Lustre: 

Adamantine to sub-metallic

Refractive Index / Birefringence: 

2.85

Pleochroism: 

Nil

Dispersion: 

-

Magnification: 

Natural inclusions.

U.V. Fluorescence: 

Inert

Spectrum: 

Not characteristic

Cause of Color: 

Copper

Treatment (Enhancement): 

-

Specific Tests & Remarks: 

Brownish red streak, soluble in hydrochloric and nitric acid

Synthesis: 

-

Simulants (with key separation tests): 

Heated Almandine Garnet (S.G., spectrum)

Geological Occurrence: 

Secondary mineral in copper deposits, sometimes coated with green malachite.

Sources: 

Namibia, Russia, Japan, U.S.A. (Arizona, New Mexico)

Cuts & Uses: 

Mostly as cabochons and beads.