mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow; Luster: Metallic; Crystal system: Isometric/Cubic; 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 system: Isometric/Cubic; Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Formed in high and low-temperature hydrothermal veins, as an accessory mineral in igneous rocks, and in sedimentary rocks through metamorphic contact or deposition in oxygen-poor environments.

Uses & applications

Used as a source of sulfur and sulfuric acid in industry; occasionally used in jewelry (labeled as marcasite); also used in early firearms and radio receivers.

Geological facts

Commonly known as "Fool's Gold" due to its similarity to real gold. It can create sparks when struck against steel, which made it a key component in flintlock-style wheel-lock firearms.

Field identification & locations

Identify by its cubic crystal habit, brittle tenacity, and greenish-black streak (real gold has a yellow streak). Found globally, with famous deposits in Spain, Italy, and the USA.