mineral

Chalcopyrite (Peacock Ore)

Chalcopyrite (CuFeS2)

Hardness: 3.5-4 (Mohs); Color: Brass yellow, often with iridescent purple, blue, and green tarnish; Luster: Metallic; Crystal Structure: Tetragonal; Cleavage: Indistinct; Specific Gravity: 4.1-4.3.

Hardness: 3
Luster: Metallic

Identified May 31, 2026More mineral →

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Physical properties

Hardness: 3.5-4 (Mohs); Color: Brass yellow, often with iridescent purple, blue, and green tarnish; Luster: Metallic; Crystal Structure: Tetragonal; Cleavage: Indistinct; Specific Gravity: 4.1-4.3.

Formation & geological history

Formed in hydrothermal veins, contact metamorphic deposits, and as a primary mineral in igneous rocks. Often found in sulfide deposits associated with volcanic activity.

Uses & applications

The most important ore of copper globally. Also popular as a display mineral for collectors due to its vibrant 'Peacock Ore' iridescence (often enhanced by acid treatment).

Geological facts

While naturally iridescent, much of the 'Peacock Ore' sold in shops is chalcopyrite that has been briefly dipped in acid to accelerate the colorful oxidation process. It is often confused with Bornite.

Field identification & locations

Identify by its metallic luster and brassy yellow internal color if chipped. Look for it in mining districts known for copper, often found alongside pyrite, quartz, and galena.