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 July 20, 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 geological environments including hydrothermal veins, contact metamorphic deposits, and as an accessory mineral in igneous and sedimentary rocks. Occurs across all geological ages.

Uses & applications

Historically a source of sulfur and sulfuric acid; used today in jewelry (marcasite jewelry), crystal healing, and as an indicator mineral in gold prospecting.

Geological facts

Often mistaken for gold due to its color and luster, but it is much harder and more brittle. It can produce sparks when struck against steel. The name comes from the Greek 'pyr' meaning fire.

Field identification & locations

Identify by its brittle nature, greenish-black streak (real gold has a yellow streak), and cubic crystal habits. Commonly found in Spain, Peru, Italy, and the USA.