mineral

Polished/tumbled metallic sulfide specimen, likely pyrite

Pyrite (FeS₂), possibly mixed with chalcopyrite or other sulfides

AI-generated identification · may be incorrect

Brassy yellow to brown-black metallic luster with granular or crystalline texture; pyrite hardness is 6–6.5 Mohs, cubic crystal system, poor cleavage, and specific gravity about 5.0. The image is too low-resolution for confident separation from marcasite or chalcopyrite.

Identified August 13, 2026More mineral →

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Physical properties

Formation & geological history

Formed in low-oxygen sedimentary environments, hydrothermal veins, and metamorphic rocks when iron and sulfur combine; specimens may range from ancient sedimentary deposits to younger hydrothermal systems. The surface appears polished or weathered rather than naturally crystal-faced.

Uses & applications

Used historically as a sulfur source and occasionally for industrial sulfuric-acid production; attractive pieces are sold as mineral specimens, but it is rarely used as jewelry because it can tarnish and oxidize.

Geological facts

Pyrite is commonly called “fool’s gold,” though it is harder and more brittle than gold and often shows a greenish-black streak. Oxidation can produce acidic runoff and rusty iron minerals.

Field identification & locations

Identify by metallic brassy color, high density, black-green streak, and lack of gold’s malleability; avoid prolonged moisture. Common localities include Peru, Spain, Italy, China, and the United States.