Rock Identifier
Peacock Ore (Bornite (Cu5FeS4) with surface tarnish) — mineral
mineral

Peacock Ore

Bornite (Cu5FeS4) with surface tarnish

Hardness: 3 on Mohs scale. Color: Iridescent blues, purples, greens, and gold due to oxidation. Luster: Metallic. Crystal System: Orthorhombic. Specific Gravity: 4.9 - 5.3.

Hardness
3 on Mohs scale
Color
Iridescent blues, purples, greens, and gold due to oxidation
Luster
Metallic
Identified More mineral
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Physical properties

Hardness: 3 on Mohs scale. Color: Iridescent blues, purples, greens, and gold due to oxidation. Luster: Metallic. Crystal System: Orthorhombic. Specific Gravity: 4.9 - 5.3.

Formation & geological history

Forms in hydrothermal veins, pegmatites, and contact metamorphic zones, often associated with other copper minerals.

Uses & applications

Used primarily as an ore of copper and widely collected and sold as an ornamental mineral specimen due to its striking iridescent colors.

Geological facts

True bornite naturally tarnishes to a bronze or copper-red color when freshly broken, but develops its famous multicolored peacock appearance upon exposure to air. Much of the commercial peacock ore is actually chalcopyrite treated with acid to enhance the tarnish.

Field identification & locations

Identify by its distinctive metallic luster, low hardness, and vibrant multicolored tarnish. Commonly sourced from major copper-producing regions worldwide.