Rock Identifier
Native copper-bearing rock (Native copper (Cu), likely with copper oxides/carbonates in a host rock) — mineral
mineral

Native copper-bearing rock

Native copper (Cu), likely with copper oxides/carbonates in a host rock

AI-generated identification · may be incorrect

Metallic to earthy luster; reddish copper-brown metal with green-blue oxidation crust, possibly mixed with pale quartz or carbonate. Native copper has Mohs hardness 2.5–3, cubic crystal structure, and very high density (about 8.9); the specimen appears irregular and partly weathered.

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Physical properties

Metallic to earthy luster; reddish copper-brown metal with green-blue oxidation crust, possibly mixed with pale quartz or carbonate. Native copper has Mohs hardness 2.5–3, cubic crystal structure, and very high density (about 8.9); the specimen appears irregular and partly weathered.

Formation & geological history

Formed in hydrothermal copper deposits when copper-rich fluids precipitated native copper in fractures and cavities, later developing green oxidation minerals such as malachite or chrysocolla. Exact age and host rock cannot be determined from the image.

Uses & applications

Collected as a mineral specimen and historically smelted for copper; copper is widely used in electrical wiring, plumbing, alloys, and roofing. Quality display pieces may have modest collector value.

Geological facts

The green-blue patina commonly reflects copper carbonate or silicate minerals produced by weathering. Native copper is malleable and leaves a copper-red streak rather than a typical rock-colored streak.

Field identification & locations

Likely from copper-producing regions such as Michigan, Arizona, Chile, or Cornwall; test with a streak plate and hardness comparison, but avoid damaging the specimen. A magnet should not attract it, and its unusual heft supports copper identification.