mineral

Pyrite (locally known as Fool's Gold)

Iron Sulfide (FeS2)

AI-generated identification · may be incorrect

Hardness: 6–6.5 (Mohs), Color: Pale brass-yellow, Luster: Metallic, Crystal system: Isometric/Cubic, Cleavage: Indistinct, Specific Gravity: 4.9–5.2

Hardness: 6–6

Identified April 10, 2026More mineral →

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Physical properties

Hardness: 6–6.5 (Mohs), Color: Pale brass-yellow, Luster: Metallic, Crystal system: Isometric/Cubic, Cleavage: Indistinct, Specific Gravity: 4.9–5.2

Formation & geological history

Formed in both igneous and sedimentary environments via hydrothermal activity or sulfur reduction. Often found in quartz veins or associated with coal beds and metamorphic rocks.

Uses & applications

Historical source of sulfur and sulfuric acid. Used as an ornamental stone in 'marcasite' jewelry and as a semiconductor in early radio receivers.

Geological facts

Its nickname 'Fool's Gold' comes from its resemblance to real gold, though it is much harder and more brittle. Unlike gold, pyrite can create sparks when struck against steel.

Field identification & locations

Identify by its hardness (cannot be scratched by a copper penny) and its blackish-green streak on a porcelain plate. Common worldwide, especially in Spain, Russia, and the USA.