mineral

Chalcopyrite

Copper Iron Sulfide (CuFeS2)

Hardness: 3.5-4.0; Color: Brass-yellow (often tarnished to irridescent green/purple); Luster: Metallic; Crystal Structure: Tetragonal; Streak: Greenish-black

Hardness: 3
Color: Brass-yellow (often tarnished to irridescent green/purple)
Luster: Metallic

Identified June 11, 2026More mineral →

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Physical properties

Hardness: 3.5-4.0; Color: Brass-yellow (often tarnished to irridescent green/purple); Luster: Metallic; Crystal Structure: Tetragonal; Streak: Greenish-black

Formation & geological history

Forms primarily in hydrothermal veins and magmatic segregations, often found in sulfide-rich regions associated with volcanic activity.

Uses & applications

The most important ore of copper; occasionally used as a decorative specimen for collectors due to its metallic luster.

Geological facts

Often called 'Peacock Ore' when it exhibits iridescent tarnishing, it is the most widespread copper-bearing mineral on Earth.

Field identification & locations

Identify by its brassy color, softness compared to pyrite (it can be scratched by a knife), and greenish-black streak. Commonly found in copper mines worldwide.