mineral

Pyrite (Fool's Gold) in Matrix

Iron Sulfide (FeS2)

Hardness: 6-6.5 Mohs. Color: Brass-yellow or gold-like. Luster: Metallic. Crystal Structure: Isometric/Cubic. Cleavage: Indistinct. Specific Gravity: 4.9-5.2.

Hardness: 6-6
Color: Brass-yellow or gold-like
Luster: Metallic

Identified April 10, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6-6.5 Mohs. Color: Brass-yellow or gold-like. Luster: Metallic. Crystal Structure: Isometric/Cubic. Cleavage: Indistinct. Specific Gravity: 4.9-5.2.

Formation & geological history

Forms in a wide variety of environments including sedimentary deposits, hydrothermal veins, and metamorphic rocks. It often crystallizes from sulfur-rich fluids in oxygen-poor environments.

Uses & applications

Historically a source of sulfur and sulfuric acid. Today, it is used as a collector specimen, in costume jewelry (marcasite jewelry), and sometimes in manufacturing lithium batteries.

Geological facts

Commonly known as 'Fool's Gold' because its color and metallic luster frequently lead novice prospectors to mistake it for real gold. Unlike gold, which is soft and malleable, pyrite is brittle and harder than a knife blade.

Field identification & locations

Identify in the field by its brittleness (it crushes to powder rather than flattening), its greenish-black streak when rubbed on unglazed porcelain, and its cubic or pyritohedral crystal habits. Commonly found in Spain, Italy, Peru, and the USA.