mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Hardness: 6-6.5 (Mohs scale), Color: Pale brass-yellow, Luster: Metallic, Crystal Structure: Isometric/Cubic, Cleavage: Indistinct, Specific Gravity: 4.8–5.0

Hardness: 6-6

Identified March 31, 2026More mineral →

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Physical properties

Hardness: 6-6.5 (Mohs scale), Color: Pale brass-yellow, Luster: Metallic, Crystal Structure: Isometric/Cubic, Cleavage: Indistinct, Specific Gravity: 4.8–5.0

Formation & geological history

Forms in a variety of environments including sedimentary deposits (in coal or shale), metamorphic rocks, and hydrothermal veins. It can be found in rocks from nearly any geological age.

Uses & applications

Historically used as a source of sulfur and for making sulfuric acid. Today, it is used in the production of lithium batteries, as a semiconductor, and widely as a lapidary material for jewelry and collecting.

Geological facts

Known as 'Fool's Gold' because its color and high density led novice prospectors to mistake it for real gold. It can spark when struck against steel, which led to its use in wheel-lock firearms.

Field identification & locations

Identify in the field by its distinct cubic crystal habit and brassy color. Unlike gold, pyrite is brittle and cannot be scratched by a copper penny. Found globally, with notable deposits in Spain, Peru, and the USA.