Bornite

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.

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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