Bornite Value, Price, and Jewelry Information


BORNITE: Butte, Montana, (specimens 2 inches across). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Bornite is suitable only for cabochons. The bronzy color rapidly tarnishes in air to a magnificent iridescent color display, mostly purple, but also with blue and green tones. Bornite is too soft and brittle for anything but a collector curiosity, although cabochons are quite attractive when they tarnish. The material is not rare, so cabochons have no great value beyond the effort of cutting.

Bornite Value

The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

Bornite Information

DataValue
NameBornite
Crystallography Tetragonal. Crystals rare, twinned; usually massive, compact.
Colors Copper red to bronze. Tarnishes to an iridescent purple color.
Luster Metallic; opaque
Fracture Uneven to conchoidal. Brittle.
Hardness 3
Specific Gravity 5.08
Cleavage Poor, indistinct. In traces on {111}.
Stone SizesCabochons could be very large, several inches long, because the massive material fromore veins are available in large pieces.
FormulaCu5FeS4

STREAK: Light grayish black.

OCCURRENCE: Low temperature copper deposits.

Bristol, Connecticut; Virginia; North Carolina; Montana; Arizona; Colorado; California

Canada; Chile; Peru; England; Italy; Germany; South Africa; Madagascar.

COMMENTS: Bornite is suitable only for cabochons. The bronzy color rapidly tarnishes in air to a magnificent iridescent color display, mostly purple, but also with blue and green tones. Bornite is too soft and brittle for anything but a collector curiosity, although cabochons are quite attractive when they tarnish. The material is not rare, so cabochons have no great value beyond the effort of cutting.

NAME:  After Ignatius von Born, eighteenth-century mineralogist.