mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Hardness: 6-6.5 Mohs; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic); Cleavage: Indistinct; Specific Gravity: 4.9-5.2

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

Identified June 21, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic); Cleavage: Indistinct; Specific Gravity: 4.9-5.2

Formation & geological history

Forms in a wide variety of geological settings, including hydrothermal veins, as an accessory mineral in igneous rocks, in contact metamorphic rocks, and in sedimentary rocks like shale and coal.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is primarily used in the production of sulfur dioxide for the paper industry, and as a popular specimen for mineral collectors.

Geological facts

Pyrite is nicknamed 'Fool's Gold' because its color and metallic luster often lead novice prospectors to mistake it for real gold. Unlike gold, pyrite is brittle and cannot be scratched by a copper penny.

Field identification & locations

Identifiable by its cubic crystal habit, brassy color, and high hardness. It produces sparks when struck against steel. Commonly found worldwide, with notable deposits in Spain, Peru, and the USA.