Pyrite

Physical Properties

Hardness: 6-6.5 on Mohs scale; Color: brass-yellow; Luster: metallic; Crystal Structure: Isometric (cubic); Cleavage: Indistinct; Specific Gravity: 4.9-5.2

Formation & Geological History

Forms in igneous, metamorphic, and sedimentary rocks via hydrothermal activity or precipitation from marine sediments in low-oxygen environments.

Uses & Applications

Used as an ore to extract sulfur for sulfuric acid production; historically used in firearms (wheel-locks); popular as an ornamental stone and in jewelry.

Geological Facts

Commonly known as Fool's Gold due to its resemblance to real gold; however, it is harder, more brittle, and creates a greenish-black streak when scratched compared to gold's yellow streak.

Field Identification & Locations

Identify by its metallic luster, golden color, and cubic crystal habits; commonly found in Spain, Peru, Italy, and the USA. Collectors look for well-defined cubes or dodecahedrons.

Identified on: 5/1/2026

Mode: Standard