mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (cubes, pyritohedrons); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

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

Identified July 11, 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 (cubes, pyritohedrons); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Formed in a variety of geological environments including hydrothermal veins, sedimentary rocks (as nodules or replacements), and contact metamorphic deposits. It can be found in rocks of almost any geological age.

Uses & applications

Major ore for sulfur and sulfuric acid; historically used to create sparks for firearms (wheel-locks); widely used in jewelry (as marcasite) and as a decorative specimen for collectors.

Geological facts

Pyrite's name comes from the Greek word 'pyr' meaning fire, because it emits sparks when struck by metal. Despite its nickname 'Fool's Gold,' it is often found in association with real gold.

Field identification & locations

Identify by its metallic luster, golden color, and brittle nature (unlike gold which is malleable). It often leaves a greenish-black streak on a porcelain plate. Common worldwide, with famous deposits in Spain, Peru, and Russia.