mineral

Pyrite

Iron Disulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: brass-yellow, metallic; Luster: metallic; Crystal structure: isometric/cubic; Cleavage: indistinct; Specific gravity: 4.8-5.0

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

Identified July 12, 2026More mineral →

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Physical properties

Hardness: 6-6.5 on Mohs scale; Color: brass-yellow, metallic; Luster: metallic; Crystal structure: isometric/cubic; Cleavage: indistinct; Specific gravity: 4.8-5.0

Formation & geological history

Forms in a wide variety of environments including igneous, metamorphic, and sedimentary rocks. Common in hydrothermal veins and as a replacement mineral in fossils.

Uses & applications

Historically a source of sulfur and sulfuric acid; used in jewelry (as 'marcasite'); sometimes used in radio receivers and paper production.

Geological facts

Often called 'Fool's Gold' due to its metallic luster and yellow hue. It can produce sparks when struck against steel, leading to its name derived from the Greek word 'pyr' meaning fire.

Field identification & locations

Identify by its cubic crystal habit, high hardness (it will scratch glass, unlike gold), and its greenish-black streak. Commonly found worldwide, notably in Spain, Italy, and the USA.