mineral

Pyrite

Iron Disulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (often cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2.

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

Identified March 4, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (often cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2.

Formation & geological history

Formed in diverse geological environments including hydrothermal veins, as an accessory mineral in igneous rocks, in contact metamorphic rocks, and in sedimentary environments (shales and coal beds) via anaerobic bacterial action. Found in geological strata ranging from Precambrian to Holocene.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is used in the production of lithium batteries, as a semiconductor material, and widely sold as a collector's specimen and in jewelry (often incorrectly termed 'marcasite' in the trade).

Geological facts

Commonly known as 'Fool's Gold' because its color and high specific gravity lead novice prospectors to mistake it for real gold. Unlike gold, pyrite is brittle and produces a greenish-black streak when rubbed on a porcelain plate.

Field identification & locations

Identify in the field by its distinct metallic brass color, cubic crystal habit, and hardness (it can scratch glass). It is found globally, with famous deposits in Spain (Rio Tinto), Peru, and the USA. Collectors look for sharp, mirror-like cubic faces.