Pyrite
Image: James Petts from London, England (CC BY-SA 2.0)
Mineral NamePyrite
Chemical FormulaFeS2
Mohs Hardness6
Crystal Systemcubic
Lustermetallic
Streak Colorgreenish-black
Cleavageindistinct/poor
Fractureconchoidal
Specific Gravity5
Colorspale brass-yellow, gold, brownish-yellow
Transparencyopaque
Type LocalityWidespread globally
Mineral GroupSulfides
Usessulfur production, collector specimens, jewelry (minor)
Associated Mineralsquartz, chalcopyrite, galena, sphalerite, gold
Raritycommon
Description
A specimen of pyrite displaying its characteristic metallic, brass-yellow luster, often tarnished or intergrown with reddish-brown iron oxides, giving it a weathered appearance.
Geological Context
Pyrite forms in a wide variety of geological environments, including hydrothermal veins, sedimentary rocks (often as concretions), metamorphic rocks, and igneous rocks, typically under reducing conditions.
