mineral

Peacock Ore

Bornite (Cu5FeS4) or iridescent Chalcopyrite (CuFeS2)

Hardness: 3-3.5 on Mohs scale. Color: Iridescent blues, purples, and magentas over a copper-red or brassy-yellow base. Luster: Metallic. Crystal Structure: Orthorhombic/Isometric. Cleavage: Poor. Specific Gravity: 4.9-5.3.

Hardness: 3-3
Luster: Metallic

Identified March 31, 2026More mineral →

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Physical properties

Formation & geological history

Formed as a primary mineral in hydrothermal veins, contact metamorphic zones, and igneous intrusions. It can also occur as a secondary mineral in the enrichment zones of copper sulfide deposits.

Uses & applications

Major ore of copper. Highly valued as a collector mineral and in metaphysical jewelry for its vibrant colors.

Geological facts

Natural Bornite tarnishes quickly when exposed to air; the 'peacock' effect is actually an oxidation layer. It is often confused with lab-treated Chalcopyrite, which is acid-washed to achieve the same rainbow effect.

Field identification & locations

Identify by its iridescent 'oil-slick' tarnish and metallic weight. Found commonly in copper-rich mining regions like Arizona (USA), Mexico, Peru, and Chile. Collectors should check the base color: reddish-brown is usually Bornite, while yellow is usually Chalcopyrite.

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