mineral

Peacock Ore

Bornite (Cu5FeS4) or iridescent Chalcopyrite (CuFeS2)

Hardness: 3-3.5 on Mohs scale; Color: Copper-red/brown on fresh surface, tarnishing to iridescent purple, blue, and gold; Luster: Metallic; Crystal Structure: Orthorhombic/Tetragonal; Cleavage: Poor/Invisible.

Hardness: 3-3
Luster: Metallic

Identified June 10, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins, contact metamorphic zones, and igneous intrusions. It is typically a primary copper mineral associated with other sulfides like pyrite and chalcocite.

Uses & applications

Primarily used as a major copper ore in the mining industry. Because of its brilliant iridescence, it is highly popular for decorative jewelry, metaphysical collections, and educational specimens.

Geological facts

The name 'Peacock Ore' is commonly used for both Bornite and acid-treated Chalcopyrite. While Bornite tarnishes naturally, many specimens sold in shops are Chalcopyrite that has been washed in acid to induce the rainbow colors.

Field identification & locations

Identify in the field by its metallic luster and the 'oil slick' rainbow tarnish. Unlike true gold, it has a greenish-black streak and is much more brittle. Common locations include Mexico, USA, and Chile.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

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

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

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

Metamorphic Rock

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic