mineral

Pyrite

Iron Sulfide (FeS2)

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

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

Identified July 19, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in a wide variety of geological settings, including hydrothermal veins, as an accessory mineral in igneous rocks, and in sedimentary rocks through biological and chemical precipitation in oxygen-poor environments.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is primarily used for jewelry (as 'marcasite'), mineral collecting, and as an ornamental stone.

Geological facts

Commonly known as 'Fool's Gold' because its color and metallic luster frequently lead novice prospectors to mistake it for gold. Unlike gold, pyrite is brittle and leaves a dark green to black streak.

Field identification & locations

Identify in the field by its cubic crystal habit, metallic luster, and hardness (it can scratch glass). Found globally, with famous deposits in Peru, Spain, and the USA. Collectors look for sharp, well-defined crystal faces.