mineral

Pyrite (Iron Pyrites)

Iron Sulfide (FeS2)

Hardness: 6-6.5 (Mohs); Color: Pale brass-yellow, tarnishing darker; Luster: Metallic; Crystal Structure: Isometric; Cleavage: Indistinct; Specific Gravity: 4.9–5.2

Hardness: 6-6
Color: Pale brass-yellow, tarnishing darker
Luster: Metallic

Identified April 12, 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: Pale brass-yellow, tarnishing darker; Luster: Metallic; Crystal Structure: Isometric; Cleavage: Indistinct; Specific Gravity: 4.9–5.2

Formation & geological history

Formed in various environments including hydrothermal veins, as an accessory mineral in igneous rocks, in sedimentary rocks through biological activity, and in contact metamorphic deposits. Often found in association with gold and copper minerals.

Uses & applications

Historically used for sulfuric acid production; currently used in jewelry (as marcasite), in lithium batteries as a cathode material, and as an ornamental gemstone for collectors.

Geological facts

Known as 'Fool's Gold' due to its resemblance to precious metal. Historically used in firearms (wheel-locks) to create sparks to ignite gunpowder. It can actually contain trace amounts of real gold within its crystal structure.

Field identification & locations

Identify by its hardness (will scratch glass, unlike gold) and its brittle nature (crushes to black powder rather than flattening). Usually found in river gravels, shale beds, and mining tailings.