Pyrite

Physical Properties

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

Formation & Geological History

Formed in igneous, metamorphic, and sedimentary environments. It creates from hydrothermal fluids or through biological activity in lack-of-oxygen marine sediments.

Uses & Applications

Source of sulfur for sulfuric acid production; occasionally used in jewelry (marcasite); potential source of gold/lithium in specific ores; historically used to spark fires.

Geological Facts

Known as 'Fool's Gold' due to its resemblance to gold; it is the most common sulfide mineral and can produce sparks when struck against steel.

Field Identification & Locations

Identify by its cubic crystal habit, high hardness (gold is soft), and blackish-green streak. Common worldwide in mining districts.

Identified on: 4/20/2026

Mode: Standard