mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5; Color: Brass-yellow; Luster: Metallic; Crystal Structure: Isometric (cubic); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Hardness: 6-6
Color: Brass-yellow
Luster: Metallic

Identified July 15, 2026More mineral →

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Physical properties

Hardness: 6-6.5; Color: Brass-yellow; Luster: Metallic; Crystal Structure: Isometric (cubic); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Forms in a variety of geological environments including sedimentary deposits, hydrothermal veins, and as an accessory mineral in igneous rocks through crystallization of iron-rich fluids.

Uses & applications

Historically used as a source of sulfur and for making sulfuric acid; currently used in jewelry (referred to as marcasite), as a collector specimen, and in lithium batteries.

Geological facts

Also known as 'Fool's Gold' due to its resemblance to real gold. It can produce sparks when struck against steel or flint, a property used by ancient cultures to start fires.

Field identification & locations

Identify by its cubic shape, striations on crystal faces, and high density. It creates a greenish-black streak when rubbed on a porcelain plate, distinguishing it from gold which leaves a yellow streak.