mineral

Pyrite in Matrix

Iron Disulfide (FeS2)

Hardness: 6-6.5 Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (cubes, pyritohedrons); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

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

Identified June 6, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (cubes, pyritohedrons); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Formed in a variety of geological environments: sedimentary rocks (anoxic conditions), metamorphic rocks, and hydrothermal veins. It results from the reaction of iron and sulfur in mineral-rich fluids.

Uses & applications

Primarily used as a source of sulfur and sulfuric acid in industry. Also popular as a collection specimen and used in ornamental jewelry (often sold as 'marcasite').

Geological facts

Commonly known as 'Fool's Gold' due to its resemblance to real gold. Unlike gold, pyrite is brittle and will shatter if struck, and it produces a greenish-black streak when rubbed on a porcelain plate.

Field identification & locations

Identify in the field by its metallic luster, golden color, and often perfectly cubic crystals. It is found globally, notably in Rio Tinto (Spain) and various locations in the US and Italy. Small matrix specimens are common in gravel and shale.