mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Cubic or pyritohedron; Cleavage: Indistinct; Specific Gravity: 4.9-5.2.

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

Identified March 7, 2026More mineral →

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Physical properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Cubic or pyritohedron; Cleavage: Indistinct; Specific Gravity: 4.9-5.2.

Formation & geological history

Formed in a variety of environments, including magmatic segregation, hydrothermal veins, and sedimentary deposits under low-oxygen conditions. It can be found in rocks of all geological ages, from Precambrian to recent.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is primarily used in the production of sulfur dioxide for the paper industry, in jewelry (often sold as 'marcasite'), and as a popular collector's specimen.

Geological facts

Pyrite gets its name from the Greek 'pyr' (fire) because it creates sparks when struck against metal or stone. It is famous for mimicking the appearance of gold, leading to its nickname 'Fool's Gold', though it is much harder and more brittle.

Field identification & locations

Identify in the field by its metallic luster, golden color, and blackish-green streak on a porcelain plate. Common locations include high-temperature hydrothermal veins and sedimentary coal beds. Collectors should look for well-defined cubic crystals.