mineral

Chalcopyrite (Peacock Ore)

Copper Iron Sulfide (CuFeS2)

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

Hardness: 3
Luster: Metallic

Identified June 29, 2026More mineral →

Explore Chalcopyrite (Peacock Ore) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

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

Formation & geological history

Formed primarily in hydrothermal veins and through magmatic segregation in igneous rocks. It is found in a wide variety of geological environments ranging from high-temperature deposits to metamorphic rocks.

Uses & applications

The primary ore of copper worldwide. While 'Peacock Ore' (often bornite-treated chalcopyrite) is popular for mineral collecting and low-end jewelry, its main industrial value is for copper extraction.

Geological facts

Chalcopyrite is often confused with Gold, earning it the nickname 'Fool's Gold,' though Pyrite is the more frequent recipient of that title. The iridescent 'Peacock' colors are actually a thin layer of oxidation on the surface.

Field identification & locations

Identify by its metallic luster and brassy yellow interior when scratched. It is softer than pyrite (which cannot be scratched by a copper penny) and produces a greenish-black streak on a porcelain plate.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Gypsum (variety Selenite or Alabaster)

Calcium sulfate dihydrate (CaSO4·2H2O)

Mineral

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock