mineral

Iridescent chalcopyrite (“peacock ore”)

Chalcopyrite, CuFeS₂, commonly surface-tarnished to bornite-like colors

AI-generated identification · may be incorrect

Brassy metallic sulfide with blue, purple, green, and gold iridescence; Mohs hardness 3.5–4, metallic luster, tetragonal crystal structure, poor cleavage, and specific gravity about 4.1–4.3. The image appears to show a small rough fragment, possibly coated or naturally tarnished.

Identified September 4, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in hydrothermal copper deposits, veins, and disseminated sulfide ores, commonly alongside pyrite, bornite, and quartz; specimens range from ancient Precambrian deposits to geologically young hydrothermal systems.

Uses & applications

Important copper ore; attractive iridescent pieces are sold as inexpensive mineral specimens and curiosities, but are generally unsuitable for fine jewelry because of softness and tarnishing.

Geological facts

The vivid colors are an oxidation or tarnish film, not the mineral’s fresh color; commercial “peacock ore” is often heat-treated chalcopyrite or bornite.

Field identification & locations

Identify by metallic brassy areas, unusually high density, softness, and rainbow tarnish; common sources include Mexico, Peru, China, and the United States. Avoid prolonged moisture and abrasion.