mineral

Pyrite (Fool's Gold) Cube

Iron Sulfide (FeS2)

AI-generated identification · may be incorrect

Hardness: 6-6.5; Color: Brass-yellow (often tarnished doll brown); Luster: Metallic; Crystal Structure: Isometric/Cubic; Cleavage: Indistinct; Specific Gravity: 4.9-5.2

Hardness: 6-6
Color: Brass-yellow (often tarnished doll brown)
Luster: Metallic

Identified May 17, 2026More mineral →

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Physical properties

Hardness: 6-6.5; Color: Brass-yellow (often tarnished doll brown); Luster: Metallic; Crystal Structure: Isometric/Cubic; Cleavage: Indistinct; Specific Gravity: 4.9-5.2

Formation & geological history

Formed in high and low temperature hydrothermal veins, as an accessory mineral in igneous rocks, and in sedimentary environments through the reduction of sulfates by organic material.

Uses & applications

A major source of sulfur for producing sulfuric acid; used in costume jewelry (marcasite), electronics (lithium-pyrite batteries), and highly valued by mineral collectors.

Geological facts

Known as 'Fool's Gold' due to its similarity to real gold, though it is much harder and more brittle. Famous cubic specimens are found perfectly formed in Navajún, Spain.

Field identification & locations

Identify by its perfect cubic shape, metallic luster, and the fact it will spark when struck with steel. Commonly found in Spain, Italy, Peru, and the USA.