mineral

Bornite (Peacock Ore)

Bornite (Cu5FeS4)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale; Color: Brownish-bronze (fresh), iridescent purple/blue (tarnished); Luster: Metallic; Crystal structure: Orthorhombic; Specific Gravity: 5.06-5.08

Hardness: 3 on Mohs scale
Color: Brownish-bronze (fresh), iridescent purple/blue (tarnished)
Luster: Metallic

Identified April 8, 2026More mineral →

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Physical properties

Hardness: 3 on Mohs scale; Color: Brownish-bronze (fresh), iridescent purple/blue (tarnished); Luster: Metallic; Crystal structure: Orthorhombic; Specific Gravity: 5.06-5.08

Formation & geological history

Formed in hydrothermal veins, contact metamorphic zones, and as a secondary mineral in enriched copper deposits. Found globally in copper-rich geological environments.

Uses & applications

A significant ore of copper, though it is also highly sought after by mineral collectors for its iridescent colors.

Geological facts

Commonly nicknamed 'peacock ore' due to its spectacular blue-purple tarnish. It was named after the Austrian mineralogist Ignaz von Born in 1845.

Field identification & locations

Identify by its iridescent 'oil-slick' tarnish and the fact that a fresh scratch reveals a bronze-colored interior. Commonly found in copper mines in locations like Arizona, Chile, and Mexico.