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: 4.9-5.2

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

Identified June 23, 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: 4.9-5.2

Formation & geological history

Formed in diverse environments including hydrothermal veins, sedimentary rocks (via biological activity), and as an accessory mineral in igneous rocks across all geological periods.

Uses & applications

Historically used to create sparks for firearms and as a source of sulfur or sulfuric acid; today it is primarily used in jewelry, collector specimens, and occasionally as an ore of gold (when it occurs as auriferous pyrite).

Geological facts

Known as Fool's Gold because its color often confused prospectors. It is the most common sulfide mineral and can actually contain small amounts of real gold hidden within its crystal structure.

Field identification & locations

Identify by its metallic luster, cubic crystal habit, and brittle nature (gold is malleable, pyrite is not). Commonly found in Spain, Italy, and the USA. When scratched on a porcelain plate, it leaves a greenish-black streak.