mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

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

Hardness: 6-6
Color: Brass-yellow, metallic
Luster: Metallic

Identified June 7, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in a wide variety of environments including sedimentary deposits, hydrothermal veins, and as an accessory mineral in igneous rocks. It can form at both high and low temperatures.

Uses & applications

Primarily used for the production of sulfur dioxide, which is used in the paper industry and for making sulfuric acid. It was historically used as a source of ignition in firearms and is now a popular collector's mineral and used in costume jewelry.

Geological facts

Pyrite is called 'Fool's Gold' because its color and high density lead many amateur prospectors to mistake it for real gold. However, pyrite is much harder and more brittle than gold and will create a black streak rather than a yellow one.

Field identification & locations

Identify by its metallic luster, brassy color, and hardness (it can scratch glass). It is often found in coal beds, as replacement fossils, and in quartz veins. Common locations include Spain, Peru, Italy, and the USA.