mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

AI-generated identification · may be incorrect

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic or octahedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2.

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

Identified May 23, 2026More mineral →

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Physical properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic or octahedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2.

Formation & geological history

Formed in diverse geological settings through magmatic segregation, hydrothermal veins, and sedimentary processes in anaerobic conditions. It can occur across all geological eras.

Uses & applications

Historically used for producing sulfuric acid and sulfur dioxide. Today, it is mainly a collector's mineral, used in jewelry (marcasite jewelry), and as a minor ore of iron/gold.

Geological facts

Known as 'Fool's Gold' because its metallic luster and yellow hue lead novice prospectors to mistake it for real gold. It sparks when struck against steel.

Field identification & locations

Identify by its brassy color, high hardness (cannot be scratched by a penny), and blackish-green streak on a porcelain plate. Found worldwide in Spain, Peru, and the USA.