mineral

Pyrite

Iron Disulfide (FeS2)

Hardness: 6-6.5 (Mohs scale), Color: Brass-yellow (pale), Luster: Metallic, Crystal Structure: Isometric (cubes, pyritohedrons), Cleavage: Indistinct, Specific Gravity: 4.9-5.2

Hardness: 6-6

Identified July 7, 2026More mineral →

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Physical properties

Hardness: 6-6.5 (Mohs scale), Color: Brass-yellow (pale), Luster: Metallic, Crystal Structure: Isometric (cubes, pyritohedrons), Cleavage: Indistinct, Specific Gravity: 4.9-5.2

Formation & geological history

Formed in hydrothermal veins, as an accessory mineral in igneous rocks, in contact metamorphic rocks, and in sedimentary rocks like coal and shale through precipitation from sulfur-rich fluids.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is used in jewelry (as marcasite), in paper production, and as a popular collector's mineral. It is also an important ore for recovering trace gold.

Geological facts

Often called 'Fool's Gold' because its color and high density resemble gold ore. In the 16th and 17th centuries, it was used as a source of ignition in early firearms (wheel-locks).

Field identification & locations

Identify by its metallic luster, brittle nature (gold is malluable), and blackish-green streak on a porcelain plate. It is found globally, with notable deposits in Spain, Peru, Italy, and the USA.