mineral

Pyrite (“fool’s gold”)

Iron disulfide, FeS₂; cubic isometric sulfide mineral

AI-generated identification · may be incorrect

Brassy yellow metallic luster, commonly granular or cubic crystals, opaque, Mohs hardness 6–6.5, specific gravity about 5.0; lacks prominent cleavage and has uneven to conchoidal fracture.

Identified September 7, 2026More mineral →

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Physical properties

Brassy yellow metallic luster, commonly granular or cubic crystals, opaque, Mohs hardness 6–6.5, specific gravity about 5.0; lacks prominent cleavage and has uneven to conchoidal fracture.

Formation & geological history

Forms in hydrothermal veins and sedimentary environments, including shale and coal beds, through sulfur–iron mineralization. Specimen age depends on locality, ranging from modern hydrothermal growth to Paleozoic and older rocks.

Uses & applications

Used historically as a minor sulfur and iron ore and occasionally for sparks; today it is mainly a teaching and collector specimen, with limited ornamental use.

Geological facts

Its metallic color resembles gold, but pyrite is harder, lighter in streak (greenish-black), and brittle; gold is softer and malleable.

Field identification & locations

Identify by brassy color, metallic luster, brittleness, dark streak, and frequent cubic faces or striations. Common localities include Spain, Peru, Italy, China, and the United States; the image appears consistent with a small pyrite aggregate.