mineral

Pyrite

Iron Disulfide (FeS2)

Hardness: 6-6.5 Mohs scale; Color: brass-yellow; Luster: metallic; Crystal structure: isometric (often cubic or pyritohedral); Cleavage: indistinct; Specific gravity: 4.8-5.0

Hardness: 6-6
Color: brass-yellow
Luster: metallic

Identified July 11, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs scale; Color: brass-yellow; Luster: metallic; Crystal structure: isometric (often cubic or pyritohedral); Cleavage: indistinct; Specific gravity: 4.8-5.0

Formation & geological history

Forms in a wide variety of geological settings, including hydrothermal veins, as a magmatic segregation mineral, and in sedimentary rocks under anaerobic conditions.

Uses & applications

Primarily used in the production of sulfur dioxide for the paper industry and sulfuric acid. It is popular as a collector's specimen and occasionally used in jewelry, marketed as 'marcasite'.

Geological facts

Commonly known as 'Fool's Gold' because its color and metallic luster often cause it to be mistaken for real gold. It can sometimes contain small amounts of actual gold.

Field identification & locations

Identify in the field by its cubic crystal habit and green-black streak. It is found globally in large quantities, with notable deposits in Spain, Italy, and the USA.