mineral

Pyrite

Iron disulfide (FeS₂), commonly called fool’s gold

AI-generated identification · may be incorrect

Brassy-yellow metallic luster with granular to cubic crystal texture; Mohs hardness 6–6.5, brittle, opaque, and specific gravity about 5.0. The specimen appears massive/granular rather than showing distinct cubes, with dark tarnishing or matrix material.

Identified August 23, 2026More mineral →

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Physical properties

Formation & geological history

Forms in oxygen-poor hydrothermal veins, sedimentary rocks, and metamorphic environments when iron and sulfur react; specimens range from Precambrian to modern geological settings. It commonly crystallizes alongside quartz, calcite, or sulfide minerals.

Uses & applications

Used historically as a sulfur source and occasionally for sulfuric-acid production; today it is mainly a teaching, decorative, and collecting mineral, with limited industrial value.

Geological facts

Its metallic color resembles gold, but pyrite is harder, more brittle, and has a dark greenish-black streak rather than gold’s yellow streak. Striking pyrite can produce sparks and a sulfurous odor.

Field identification & locations

Identify it by brass color, metallic luster, high density, hardness, and dark streak; a steel file generally fails to scratch it, while gold is much softer. Common localities include Spain, Peru, Italy, China, and the United States.