mineral

Pyrite (Fool's Gold) in Matrix

Iron Disulfide (FeS2)

AI-generated identification · may be incorrect

Hardness: 6-6.5 Mohs; Color: brassy yellow/metallic gold; Luster: metallic; Crystal structure: Isometric/cubic; Streak: greenish-black; Specific gravity: approx. 5.0

Hardness: 6-6
Color: brassy yellow/metallic gold
Luster: metallic

Identified July 13, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs; Color: brassy yellow/metallic gold; Luster: metallic; Crystal structure: Isometric/cubic; Streak: greenish-black; Specific gravity: approx. 5.0

Formation & geological history

Forms in a wide variety of environments including sedimentary deposits (organic-rich), hydrothermal veins, and metamorphic rocks. Often occurs in igneous rocks as an accessory mineral.

Uses & applications

Used commercially for the production of sulfur dioxide and sulfuric acid. Popular as a collector specimen and occasionally in jewelry as marcasite. Historical use as a fire starter.

Geological facts

Nicknamed 'Fool\'s Gold' because its color often confused prospectors. Unlike real gold, pyrite is brittle and leaves a greenish-black streak when rubbed on a porcelain plate, while gold leaves a yellow streak.

Field identification & locations

Identified by its brassy metallic luster and cubic crystal habit. Commonly found globally in Spain, Peru, and the USA. Collectors look for sharp, well-defined cubic or pyritohedron faces.