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| Name Origin | Bornite was named after Ignatius von Born, eighteenth-century mineralogist |
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| Chemical Formula | Cu5FeS4 |
| Color | Copper red to bronze. Tarnishes to an iridescent purple color |
| Fracture | uneven to conchoidal, Brittle |
| Hardness | 3 on the Mohs scale |
| Crystal System | Tetragonal. Crystals rare, twinned; usually massive, compact |
| Cleavage | Traces |
| Specific Gravity (SG) | 5.08 |
| Lustre | Metallic; opaque |
Note: 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 greentones. 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 speciment
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Bornite Mineral
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