mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 Mohs scale; Color: brass-yellow, pale gold; Luster: metallic; Crystal structure: isometric (cubic, pyritohedral); Cleavage: poor/indistinct; Specific gravity: 4.8-5.0

Hardness: 6-6
Color: brass-yellow, pale gold
Luster: metallic

Identified May 10, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs scale; Color: brass-yellow, pale gold; Luster: metallic; Crystal structure: isometric (cubic, pyritohedral); Cleavage: poor/indistinct; Specific gravity: 4.8-5.0

Formation & geological history

Formed in high and low temperature hydrothermal veins, by magmatic segregation, in metamorphic rocks, and as a replacement mineral in sedimentary rocks. Can be found in geological formations from nearly all eras.

Uses & applications

Historically used for sulfuric acid production and as a spark-generator for firearms. Today used as a source of iron, for lapidary work, jewelry (labeled as marcasite), and as collector specimens.

Geological facts

Commonly known as Fool's Gold because its color and high density lead novice prospectors to mistake it for real gold. Unlike real gold, it is brittle and will shatter if struck, rather than flattening.

Field identification & locations

Identify in the field by its cubic crystal habit, brittle nature, and greenish-black streak when rubbed on a porcelain plate. Found globally, with notable deposits in Spain, Peru, and the USA.