mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 Mohs scale; Color: Brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic, octahedral, or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

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

Identified June 6, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs scale; Color: Brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic, octahedral, or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Formed in high and low-temperature hydrothermal veins, as an accessory mineral in igneous rocks, and in sedimentary rocks such as shale and coal. It can be found in rocks from nearly all geological ages.

Uses & applications

Used industrially to produce sulfur dioxide (for sulfuric acid) and iron. It is popular as a collector's mineral and sometimes used in costume jewelry (often called 'marcasite'). Historical use as a flint substitute to create sparks.

Geological facts

Often called 'Fool's Gold' because its color resembles gold, though it is much harder and more brittle. Pyrite can actually contain small amounts of actual gold hidden within its crystal structure.

Field identification & locations

Identify by its metallic luster, 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.