mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (often cubic or octahedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2

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

Identified July 10, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (often cubic or octahedral); Cleavage: Indistinct; Specific Gravity: 4.9-5.2

Formation & geological history

Formed in diverse geological environments including hydrothermal veins, sedimentary rocks through biological activity, and as an accessory mineral in igneous rocks. Found in strata ranging from Precambrian to recent times.

Uses & applications

Used historically as a source of ignition (fire-striking), in the production of sulfuric acid, and frequently used in jewelry (as marcasite) and as popular collector specimens.

Geological facts

Commonly known as 'Fool's Gold' due to its resemblance to gold. Unlike gold, pyrite is brittle and leaves a greenish-black streak when rubbed on a porcelain plate. It can actually contain small amounts of actual gold hidden within its crystal structure.

Field identification & locations

Identify by its brassy color, metallic luster, and the cubic shape of its crystals. It is found globally, with notable deposits in Spain, Peru, and the USA. Collectors look for sharp crystal faces and high luster.