mineral
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
Hardness of 3.5 to 4 on the Mohs scale, brass-yellow to golden-yellow color often with iridescent purple, blue, and green tarnish (peacock ore), metallic luster, tetragonal crystal system, specific gravity of 4.1 to 4.3.
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Physical properties
Hardness of 3.5 to 4 on the Mohs scale, brass-yellow to golden-yellow color often with iridescent purple, blue, and green tarnish (peacock ore), metallic luster, tetragonal crystal system, specific gravity of 4.1 to 4.3.
Formation & geological history
Formed mainly in hydrothermal veins and associated with sulfide mineral deposits. Can be found in igneous, sedimentary, and metamorphic environments worldwide.
Uses & applications
Primary ore of copper; also popular among mineral collectors as a display specimen, especially when treated to enhance its colorful peacock tarnish.
Geological facts
Often nicknamed 'peacock ore' or 'fool's gold' due to its bright metallic colors and superficial resemblance to pyrite and gold, though it is softer and tarnishes differently.
Field identification & locations
Easily identified by its distinctive iridescent colors and lower hardness than pyrite. Found globally in major copper-producing regions such as the USA, Chile, Mexico, and Peru.
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