mineral

Pyrite

Iron Sulfide (FeS2)

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

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

Identified May 30, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in high and low-temperature hydrothermal veins, by magmatic segregation, or as an accessory mineral in igneous rocks. It also occurs in sedimentary rocks through organic decay in oxygen-poor environments.

Uses & applications

Used as a source of sulfur and sulfuric acid in the chemical industry. Historically used in firearms (wheel-locks). Today, it is popular for jewelry (marcasite jewelry), decorative specimens, and metaphysical collecting.

Geological facts

Commonly known as Fool's Gold due to its resemblance to precious metal. Unlike gold, pyrite is brittle and leaves a greenish-black streak when rubbed on a streak plate. It can actually spark when struck against steel.

Field identification & locations

Identify by its hardness (cannot be scratched by a penny), brass-yellow color, and cubic crystal habit. Found globally, with notable deposits in Peru, Spain, and its abundance in coal seams and metamorphic shales.