mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to brass-yellow; Luster: Metallic; Crystal Structure: Isometric/Cubic; Cleavage: Poor/Indistinct; Specific Gravity: 4.9-5.2.

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

Identified July 8, 2026More mineral →

Explore Pyrite in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to brass-yellow; Luster: Metallic; Crystal Structure: Isometric/Cubic; Cleavage: Poor/Indistinct; Specific Gravity: 4.9-5.2.

Formation & geological history

Forms in a variety of geological settings including hydrothermal veins, as an accessory mineral in igneous rocks, in contact metamorphic rocks, and in sedimentary rocks such as shale and coal. It forms at both high and low temperatures.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today it is used in jewelry (often called 'marcasite' in the trade), as a collector's specimen, and occasionally in the production of lithium-ion batteries.

Geological facts

Commonly known as 'Fool's Gold' because its color and metallic luster often lead novice prospectors to mistake it for real gold. It can create sparks when struck against steel, a property used in ancient flintlock firearms.

Field identification & locations

Identify by its cubic crystal habit, brassy color, and greenish-black streak. Unlike gold, it is brittle and will shatter rather than flatten. Common locations include Peru, Spain, Italy, and the USA (Arizona, Colorado).