mineral

Chalcopyrite in Quartz (Gold-bearing Ore)

CuFeS2 (Chalcopyrite)

Hardness: 3.5-4 (mineral) / 7 (quartz host); Color: Brass-yellow to golden brown; Luster: Metallic; Crystal Structure: Tetragonal; Cleavage: Poor; Specific Gravity: 4.1-4.3

Hardness: 3
Color: Brass-yellow to golden brown
Luster: Metallic

Identified June 27, 2026More mineral →

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Physical properties

Hardness: 3.5-4 (mineral) / 7 (quartz host); Color: Brass-yellow to golden brown; Luster: Metallic; Crystal Structure: Tetragonal; Cleavage: Poor; Specific Gravity: 4.1-4.3

Formation & geological history

Formed in hydrothermal veins and through magmatic segregation. Found in various geological ages where sulfide minerals precipitate from hot, metal-rich fluids in crustal fractures.

Uses & applications

Primary ore of copper; occasionally serves as an ore for gold if present in sufficient quantities; sold as decorative 'Peacock Ore' when tarnished; used in mineral collections.

Geological facts

Chalcopyrite is often confused with gold, earning it the nickname 'Fool's Gold', though it is more brassy than actual gold. In many mining districts, it is a primary indicator for the presence of precious metals.

Field identification & locations

Identified by its metallic brassy luster and greenish-black streak. Look for it in quartz veins or massive sulfide deposits. It is softer than pyrite and will not scratch glass.

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