Rock Identifier
Peacock ore (iridescent chalcopyrite) (Chalcopyrite, CuFeS₂, commonly surface-treated to enhance iridescence) — mineral
mineral

Peacock ore (iridescent chalcopyrite)

Chalcopyrite, CuFeS₂, commonly surface-treated to enhance iridescence

AI-generated identification · may be incorrect

Brassy metallic sulfide with vivid purple, blue, pink, and gold tarnish; Mohs hardness 3.5–4, poor cleavage, uneven fracture, tetragonal crystal structure, and specific gravity about 4.1–4.3. The rainbow colors are an oxidation film, often artificially intensified with acid or heat.

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Physical properties

Brassy metallic sulfide with vivid purple, blue, pink, and gold tarnish; Mohs hardness 3.5–4, poor cleavage, uneven fracture, tetragonal crystal structure, and specific gravity about 4.1–4.3. The rainbow colors are an oxidation film, often artificially intensified with acid or heat.

Formation & geological history

Forms mainly in hydrothermal copper deposits, commonly with pyrite, bornite, quartz, and sphalerite; most specimens formed during Paleozoic to Mesozoic ore-forming events, though deposits range widely in age.

Uses & applications

Collected as a colorful mineral specimen and occasionally used as a copper ore; it is generally too soft and unstable for durable jewelry.

Geological facts

“Peacock ore” is a trade name, not a distinct mineral; naturally iridescent chalcopyrite is often confused with bornite, which is harder and commonly more copper-rich.

Field identification & locations

Identify by metallic luster, brassy base color, rainbow tarnish, softness, and possible green-black streak; common localities include Mexico, Peru, the United States, China, and Australia.