mineral

Pyrite

Iron disulfide (FeS2)

Commonly known as Fool's Gold; Hardness: 6-6.5 Mohs scale; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (cubes, pyritohedrons); Cleavage: Poor; Specific Gravity: 4.9–5.2

Hardness: 6-6
Color: Pale brass-yellow
Luster: Metallic

Identified June 3, 2026More mineral →

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Physical properties

Commonly known as Fool's Gold; Hardness: 6-6.5 Mohs scale; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (cubes, pyritohedrons); Cleavage: Poor; Specific Gravity: 4.9–5.2

Formation & geological history

Formed in diverse geological environments including hydrothermal veins, sedimentary rocks under reducing conditions, and as an accessory mineral in igneous rocks. Found in geological formations ranging from Precambrian to Holocene.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today used in lithium batteries, as a semiconductor material, and for jewelry (marcasite jewelry) and decorative specimen collecting.

Geological facts

The name comes from the Greek word 'pyr' meaning fire, because it creates sparks when struck against metal. It has a greenish-black streak, which helps distinguish it from real gold (which has a golden yellow streak).

Field identification & locations

Identified in the field by its brittle nature (gold is malleable), metallic luster, and brassy color. Commonly found worldwide, with notable deposits in Spain, Peru, Italy, and the USA.