mineral

Pyrite (Iron Pyrites)

Iron Sulfide (FeS2)

Hardness: 6-6.5 Mohs; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal system: Isometric (often cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

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

Identified March 19, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal system: Isometric (often cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Formed in high and low temperature hydrothermal veins, by magmatic segregation, or as an accessory mineral in igneous, metamorphic, and sedimentary rocks. Common in coal beds and as replacement fossils.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is used in the manufacture of lithium batteries, as a semiconductor material, for jewelry (often sold as 'marcasite'), and as a popular collector specimen.

Geological facts

Commonly known as 'Fool's Gold' due to its deceptive color. It can produce sparks when struck against steel. Ancient Romans used it for fire-making, and its name is derived from the Greek word 'pyr' meaning fire.

Field identification & locations

Identify by its cubic crystal habit, brassy color, and high density. It creates a greenish-black streak when rubbed on a porcelain plate, distinguishing it from real gold's yellow streak. Found globally, specifically in Spain, Peru, and the USA.