mineral

Pyrite

Iron Sulfide (FeS2)

AI-generated identification · may be incorrect

Hardness: 6-6.5 Mohs; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric; Cleavage: Indistinct; Specific Gravity: 4.9-5.2; Streak: Greenish-black to brownish-black

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

Identified July 13, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric; Cleavage: Indistinct; Specific Gravity: 4.9-5.2; Streak: Greenish-black to brownish-black

Formation & geological history

Formed in high and low-temperature hydrothermal veins, also by magmatic segregation, in contact metamorphic deposits, and as an accessory mineral in sedimentary and igneous rocks.

Uses & applications

Source of sulfur and sulfuric acid; historical use in ignition mechanisms for firearms; popular as collector specimens and sometimes used in gemstone jewelry (often incorrectly called 'marcasite').

Geological facts

Known as 'Fool's Gold' due to its deceptive color; it can spark when struck against steel. It is the most common sulfide mineral on Earth.

Field identification & locations

Identify by its hardness (harder than gold, it will scratch glass) and its greenish-black streak. Commonly found in Spain, Italy, Peru, and the USA. Collectors look for well-defined cubic or pyritohedron crystal shapes.