Bornite was named for the Austrian mineralogist Ignatius von Born. It is an important ore of copper and is commonly found associated with other sulfide minerals. Fresh surfaces of bornite are a brownish-bronze color but these surfaces tarnish quickly to a metallic blue/purple giving bornite the name "peacock ore". Continued tarnishing darkens the mineral to black. Bornite alters readily to the minerals covellite and chalcopyrite.
| Cu5FeS4 |
|
| Sulfide |
|
| Tetragonal (below 228oC), Isometric (above 228oC) |
|
| -42m |
|
| 3 |
|
| 5.06-5.08 |
|
| {111} imperfect |
|
| Conchoidal |
|
| Black, midnight blue/purple, brownish-bronze on fresh exposures |
|
| Grayish-black |
|
| Metallic |
|
| Opaque |
|
| Massive, reniform |
|
| Becomes magnetic when heated |
|
| Notable Localities: |
Bristol, Connecticut; Cornwall, England; Chile; Peru; Mexico |
| Uses: |
Copper ore |
Specimens:
| |
