mineral

Pyrite

Iron Disulfide (FeS2)

Hardness: 6–6.5 Mohs scale; Color: Pale brass-yellow with occasional tarnishing; Luster: Metallic; Crystal Structure: Isometric (cubic, pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.9–5.2

Hardness: 6–6
Color: Pale brass-yellow with occasional tarnishing
Luster: Metallic

Identified March 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms in a wide range of geological environments, including hydrothermal veins, as an accessory mineral in igneous rocks, in sedimentary environments with low oxygen (like black shales), and in metamorphic rocks. It spans across all geological ages from Archean to Holocene.

Uses & applications

Historically used as a source of sulfur for sulfuric acid production; currently used in jewelry (marketed as 'marcasite'), in lithium batteries (cathodes), and for paper manufacturing. It is also a very popular specimen for mineral collectors.

Geological facts

Known as 'Fool's Gold' because its color and weight sometimes led prospectors to believe they had found real gold. Unlike gold, pyrite is brittle and leaves a greenish-black streak on a porcelain plate, whereas gold leaves a yellow streak.

Field identification & locations

Identify in the field by its metallic luster, golden hue, and cubic crystal shapes. It is ubiquitous worldwide, with notable deposits in Spain, Peru, Italy, and the USA. Collectors look for sharp, mirror-finished cubes or sun-disc formations.