mineral

Native copper-bearing sulfide specimen

Likely chalcopyrite (CuFeS₂), possibly with native copper and iron oxides

AI-generated identification · may be incorrect

Metallic luster with brassy, silver-gray, and reddish-orange tarnish; likely Mohs hardness 3.5–4, opaque, massive to granular, with indistinct cleavage. The reddish coating may be copper or oxidation products rather than intrinsic color.

Identified August 20, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal copper deposits, commonly in veins and disseminated ore; mineralization ranges from Precambrian to geologically recent. Exact identification and age require testing or locality information.

Uses & applications

Copper sulfide ores are mined for copper; attractive iridescent pieces are collected, though this small specimen has limited jewelry use and is not suitable for construction.

Geological facts

Chalcopyrite commonly develops blue, purple, or reddish “peacock ore” tarnish. A streak test, hardness test, and specific-gravity measurement can distinguish it from bornite, copper metal, and metallic slag.

Field identification & locations

Common localities include Chile, Peru, Mexico, the United States, Canada, and Australia. Confirm with a dark greenish-black streak, moderate hardness, and lack of strong malleability; an acid or laboratory test can verify copper minerals.