mineral

Pyrite (iron pyrite)

Pyrite, FeS₂; cubic/isometric iron sulfide

AI-generated identification · may be incorrect

Brassy yellow metallic luster with abundant small cubic or pyritohedral crystal faces; typically opaque and brittle. Mohs hardness 6–6.5, specific gravity about 5.0, and poor-to-indistinct cleavage; the specimen appears cut or assembled from crystalline material.

Identified September 12, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in hydrothermal veins and sedimentary environments, including coal beds and black shale, where iron-bearing fluids react with sulfur. Pyrite occurs from Precambrian rocks to modern deposits and is widespread worldwide.

Uses & applications

Used historically as a sulfur source and currently for sulfuric-acid production, mineral collecting, decorative objects, and jewelry-like cabochons; it is not generally used as a precious gemstone because it can tarnish and fracture.

Geological facts

Its bright metallic appearance gives rise to the nickname “fool’s gold,” though its cubic crystal habit and greater hardness distinguish it from gold. Oxidation can produce iron oxides and acidic drainage.

Field identification & locations

Identify by brass-yellow color, metallic luster, cubic crystals, blackish-green streak, and lack of malleability; gold is softer, denser, and malleable. Common localities include Spain, Peru, Italy, China, the United States, and Canada.