mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

AI-generated identification · may be incorrect

Hardness: 6-6.5; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric; Cleavage: Indistinct; Specific Gravity: 4.8-5.0

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

Identified March 12, 2026More mineral →

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Physical properties

Hardness: 6-6.5; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric; Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Formed in hydrothermal veins, by magmatic segregation, and as an authigenic mineral in sedimentary rocks; present in environments ranging from precambrian to modern day.

Uses & applications

Used commercially for the production of sulfuric acid and sulfur dioxide; occasionally used in jewelry (marcasite) and as a collector's specimen.

Geological facts

Known as Fool's Gold due to its visual similarity to real gold; however, it is harder and leaves a greenish-black streak when scratched on porcelain.

Field identification & locations

Identified by its brassy color, cubic crystal habit, and high hardness; common in many geological settings worldwide; collectors should look for well-defined cubic or pyritohedral faces.