mineral

Peacock Ore

Bornite (Cu5FeS4)

Hardness: 3 (Mohs scale); Color: Iridescent blue, purple, and green (tarnish); Luster: Metallic; Crystal Structure: Orthorhombic/Isometric; Cleavage: Poor; Specific Gravity: 5.06-5.08

Hardness: 3 (Mohs scale)
Color: Iridescent blue, purple, and green (tarnish)
Luster: Metallic

Identified April 5, 2026More mineral →

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Physical properties

Hardness: 3 (Mohs scale); Color: Iridescent blue, purple, and green (tarnish); Luster: Metallic; Crystal Structure: Orthorhombic/Isometric; Cleavage: Poor; Specific Gravity: 5.06-5.08

Formation & geological history

Formed in copper deposits through hydrothermal processes, typically in igneous and metamorphic rocks. Most specimens are from primary magmatic segregation or contact metamorphism.

Uses & applications

Major ore of copper; highly popular as a decorative display mineral for collectors and metaphysical users.

Geological facts

Natural Bornite is bronze-brown but tarnishes quickly to iridescent colors. Many specimens sold as 'Peacock Ore' in shops are actually Chalcopyrite that has been acid-washed to artificially induce rainbows.

Field identification & locations

Identified by its distinctive multi-colored tarnish (like a peacock's tail) and its grayish-black streak. Commonly found in copper mines in Mexico, Arizona, and Cornwall.