Copper Iron Sulfide
Cu5FeS4
The bornite chunks sold as 'peacock ore' or 'peacock copper' have a rich bouquet of colors.
The History Says
Bornite is known since 1725, but not given its name until 1845 when it was named for Ignaz von Born (1742-1791), Austrian Mineralogist.
The Present Scenario
Bornite is important for its copper content, that is about 63 percent by mass, and is used in copper industries.
BORNITE IS a sulfide mineral and one of the important copper ore mineral. It crystallizes in the cubic system. On fresh surfaces, it has a brown to copper-red color which tarnishes to an irrdescent purple surface. Due to the purple to bronze irridescence, it is also called 'peacock ore.'
Bornite widely occurs in porphyry copper deposits along with chalcopyrite. Both the chalcopyrite and bornite are typically replaced by chalcocite and covellite in supergene enrichment zone of copper deposits. It is also found in pegmatites.
Physical Properties of Bornite
| Color | Brown to black with a typical purplish-bluish tarnish, a reddish bronze color on freshly broken surfaces. |
| Luster | Metallic |
| Transparency | Crystals are opaque |
| Cleavage | Very poor, octahedral |
| Fracture | Conchoidal |
| Hardness | 3 |
| Specific gravity | Approximately 4.9 - 5.3 |
| Streak | Gray black |
Associated Minerals of Bornite
- Magnetite
- Chalcocite
- Chalcopyrite
- Covellite
- Pyrrhotite
- Pyrite
- Other sulfides
Uses of Bornite
- As a specimen
- For extracting copper
Occurrences of Bornite
- Bristol, Connecticut, Butte, Montana, Arizona in the USA
- Cornwall, England
- Rhineland, Germany
- Tsumeb, Namibia
- South Africa
- Morocco
- Bolivia