mineral

Pyrite

Iron Disulfide (FeS2)

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

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

Identified May 11, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in diverse geological settings through hydrothermal veins, as an accessory mineral in igneous rocks, in contact metamorphic deposits, and in sedimentary rocks like shale and coal.

Uses & applications

Historically used for sulfur and sulfuric acid production; common in jewelry (referred to as marcasite), and highly popular as a collectible mineral specimen.

Geological facts

Nickname is 'Fool's Gold' because its color and weight can lead beginners to mistake it for real gold. Unlike gold, pyrite is brittle and leaves a greenish-black streak on porcelain.

Field identification & locations

Identify in the field by its brassy color, hardness (it can scratch glass), and cubic crystal habit. Found worldwide with notable deposits in Spain, Peru, and the United States.