mineral

Peacock Ore

Bornite (Cu5FeS4) or Chalcopyrite treated with acid

Hardness: 3-3.25; Color: Iridescent metallic purple, blue, gold, and green; Luster: Metallic; Crystal Structure: Orthorhombic/Isometric; Cleavage: Poor; Specific Gravity: 5.06-5.08

Hardness: 3-3
Color: Iridescent metallic purple, blue, gold, and green
Luster: Metallic

Identified June 21, 2026More mineral →

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Physical properties

Hardness: 3-3.25; Color: Iridescent metallic purple, blue, gold, and green; Luster: Metallic; Crystal Structure: Orthorhombic/Isometric; Cleavage: Poor; Specific Gravity: 5.06-5.08

Formation & geological history

Formed in hydrothermal veins, contact metamorphic zones, and magmatic segregations. Often associated with other copper minerals like chalcocite and malachite.

Uses & applications

Bornite is a significant copper ore for industrial copper extraction. More commonly, these vibrant iridescent specimens are used in the metaphysical and rock collecting markets.

Geological facts

Natural Bornite tarnishes quickly to iridescent colors, but most 'brightly' colored specimens in shops are actually Chalcopyrite that has been intentionally treated with acid to produce a false iridescence.

Field identification & locations

Identify by its distinctive 'rainbow' tarnish. It can be distinguished from Chalcopyrite by its softer texture and the fact that it tarnishes to darker blues and purples rather than remaining brass-yellow.

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

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral