mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden-yellow; Luster: Metallic; Crystal Structure: Isometric/Cubic (often forming pyritohedrons or cubes with striations); Cleavage: Indistinct; Specific Gravity: 4.9–5.2.

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

Identified March 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms in a variety of geological settings including hydrothermal veins, as an accessory mineral in igneous rocks, in contact metamorphic rocks, and as a replacement mineral in sedimentary rocks (shale, coal). It occurs across all geological eras and is often found near quartz veins or coal beds.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is used in the manufacture of paper, fertilizers, and explosives. It is also a popular collector's mineral and is occasionally used in marcasite-style jewelry or as an ornamental stone.

Geological facts

Famous for being called 'Fool's Gold' due to its resemblance to precious metals. During the 16th and 17th centuries, it was used as a spark-producing mechanism in wheel-lock firearms. It is actually harder than gold and will leave a green-black streak on a porcelain plate, whereas gold leaves a yellow streak.

Field identification & locations

Identify in the field by its brassy metallic luster, cubic crystal habit, and brittle nature (it breaks/powders under pressure while gold is malleable). Common locations include Spain (Rio Tinto), Peru, Italy, and various mines in the USA (e.g., Colorado, Pennsylvania). Collectors often find it in mine tailings or stream beds.