Rock Identifier
Likely raw chalcopyrite or bornite specimen (Chalcopyrite (CuFeS₂), possibly bornite (Cu₅FeS₄)) — mineral
mineral

Likely raw chalcopyrite or bornite specimen

Chalcopyrite (CuFeS₂), possibly bornite (Cu₅FeS₄)

AI-generated identification · may be incorrect

Brassy bronze to iridescent copper-gold color with metallic luster; typically Mohs hardness 3.5–4, opaque, and lacking obvious cleavage. The small, partly obscured specimen appears metallic and sulfide-like, but image quality prevents confident separation from other copper sulfides.

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Physical properties

Brassy bronze to iridescent copper-gold color with metallic luster; typically Mohs hardness 3.5–4, opaque, and lacking obvious cleavage. The small, partly obscured specimen appears metallic and sulfide-like, but image quality prevents confident separation from other copper sulfides.

Formation & geological history

Forms mainly in hydrothermal copper deposits, veins, and porphyry systems through precipitation from hot, sulfur-rich fluids; commonly associated with pyrite, quartz, and other sulfides. Its age depends on the deposit, ranging from Precambrian to modern geological settings.

Uses & applications

Important copper ore for electrical wiring, plumbing, alloys, and industrial products; attractive iridescent pieces are collected, though they are rarely used as durable gemstones.

Geological facts

Chalcopyrite is the most abundant copper sulfide mineral and often develops colorful tarnish called peacock ore; bornite naturally shows stronger purple-blue iridescence. Tarnish can be artificially enhanced on commercial specimens.

Field identification & locations

Look for high density, metallic luster, brassy color, and a dark streak; chalcopyrite is softer than pyrite and may scratch more easily. Common localities include Peru, Mexico, the United States, Canada, Australia, and China.