mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow with submetallic luster; Crystal structure: Cubic (isometric); Cleavage: Indistinct; Specific Gravity: 4.8-5.0.

Hardness: 6-6
Color: Pale brass-yellow with submetallic luster

Identified June 2, 2026More mineral →

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Physical properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow with submetallic luster; Crystal structure: Cubic (isometric); Cleavage: Indistinct; Specific Gravity: 4.8-5.0.

Formation & geological history

Forms in a variety of environments including sedimentary deposits (where it may replace organic material), metamorphic rocks, and hydrothermal veins. It can form at high or low temperatures.

Uses & applications

Primarily used in the production of sulfur dioxide for sulfuric acid, though historically used as a spark source in firearms. In jewelry, it is sold as 'marcasite'.

Geological facts

Often called 'Fool's Gold' due to its deceptive color. It can actually contain trace amounts of real gold and arsenic. It is the most common sulfide mineral on the Earth's surface.

Field identification & locations

Identify in the field by its cubic crystal habit, brittle nature, and greenish-black streak (real gold has a yellow streak). Found globally, commonly in coal seams and quartz veins.