mineral

Pyrite

Iron Sulfide (FeS2)

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

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

Identified May 21, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in high and low temperature hydrothermal veins, by magmatic segregation, as an accessory mineral in igneous rocks, and in sedimentary rocks such as shale and coal. It can be found in rocks of all geological ages.

Uses & applications

Historically used as a source of sulfur for sulfuric acid. Used today in jewelry (often sold as 'marcasite'), as a collector's specimen, and occasionally in the production of lithium-iron batteries.

Geological facts

Commonly known as 'Fool's Gold' because its color and metallic luster often led novice prospectors to mistake it for gold. Unlike gold, pyrite is brittle and leaves a greenish-black streak on a ceramic plate.

Field identification & locations

Identify in the field by its brassy color, hardness (it can scratch glass), and its tendency to form cubic shapes. It is found worldwide, with notable deposits in Spain, Peru, and various parts of the USA.