mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

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

Identified June 2, 2026More mineral →

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Physical properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Formed in a variety of geological environments including hydrothermal veins, sedimentary rocks (as concretions), and metamorphic rocks. It forms in conditions of low oxygen and presence of sulfur.

Uses & applications

Primarily used as an ore of sulfur for sulfuric acid production. Historically used in the ignition of firearms (wheel-locks) and as a semi-precious stone in Victorian jewelry known as 'marcasite'.

Geological facts

Often called 'Fool\'s Gold' because its color and metallic luster frequently led inexperienced prospectors to believe they had found gold. It is the most common sulfide mineral.

Field identification & locations

Identify by its brittle nature and greenish-black streak (gold is malleable and has a yellow streak). Commonly found in coal beds, quartz veins, and shales globally.