Pyrite

Physical Properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric (often cubic or pyritohedral); Cleavage: Indistinct; Specific Gravity: 4.8-5.0

Formation & Geological History

Formed in a variety of environments including magmatic segregation, hydrothermal veins, and as a sedimentary authigenic mineral in anoxic environments. It can be found in rocks of all geological ages.

Uses & Applications

Historically used as a source of sulfur and sulfuric acid. Today, it is used in the manufacture of lithium batteries, as a localized semiconductor material, and as a popular ornamental stone/collector specimen.

Geological Facts

Commonly known as 'Fool's Gold' because its color and metallic luster frequently lead novice prospectors to mistake it for real gold. Unlike gold, it is brittle and will powder when crushed rather than flatten.

Field Identification & Locations

Identify by its golden metallic luster and its blackish-green streak on a porcelain plate. It is found globally, notably in Spain (Rio Tinto), Italy, and the USA. Collectors look for well-defined cubic crystals.

Identified on: 4/14/2026

Mode: Standard