mineral

Pyrite (Fool's Gold)

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: 4.8-5.0

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

Identified June 17, 2026More mineral →

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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: 4.8-5.0

Formation & geological history

Formed in diverse environments including hydrothermal veins, as a magmatic segregation mineral, in sedimentary rocks through anaerobic bacterial action, and in contact metamorphic deposits. It can be found in rocks from virtually all geological ages.

Uses & applications

Historically a source of sulfur and sulfuric acid; used in the manufacturing of lithium batteries, glass, and as a semiconductor. Popular as a collector's specimen and in costume jewelry.

Geological facts

Pyrite is nicknamed 'Fool's Gold' because its color and metallic luster often led novice prospectors to mistake it for real gold. Some specimens contain small amounts of actual gold hidden within the crystal lattice.

Field identification & locations

Identify in the field by its brittle nature (gold is malleable), black/greenish streak on a porcelain plate, and distinct cubic crystal habits. Found globally with famous deposits in Spain, Italy, and the USA.