mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Hardness: 6-6.5 (Mohs scale); Color: Brassy yellow or pale gold; Luster: Metallic; Crystal Structure: Isometric (cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2

Hardness: 6-6
Color: Brassy yellow or pale gold
Luster: Metallic

Identified July 21, 2026More mineral →

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Physical properties

Hardness: 6-6.5 (Mohs scale); Color: Brassy yellow or pale gold; Luster: Metallic; Crystal Structure: Isometric (cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2

Formation & geological history

Forms in a wide variety of geological settings including hydrothermal veins, as an accessory mineral in igneous rocks, and in sedimentary rocks through biological activity in low-oxygen environments.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is primarily used for jewelry (as marcasite), in solar panels, lithium batteries, and as a popular specimen for mineral collectors.

Geological facts

Pyrite is nicknamed 'Fool's Gold' because its metallic luster and brassy color lead many inexperienced prospectors to mistake it for real gold. Unlike gold, pyrite is brittle and leaves a greenish-black streak.

Field identification & locations

Identified in the field by its metallic luster, hardness (it can scratch glass), and cubic crystal habit. Commonly found globally, with notable deposits in Spain, Peru, Italy, and the USA (Arizona/Pennsylvania).