Pyrite
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Mineral NamePyrite
Chemical FormulaFeS2
Mohs Hardness6
Crystal Systemcubic
Lustermetallic
Streak Colorgreenish-black
Cleavageindistinct
Fractureconchoidal to uneven
Specific Gravity5
Colorspale brass-yellow, golden
Transparencyopaque
Type LocalityAmpliación a Victoria Mine, Navajún, La Rioja, Spain
Mineral GroupSulfides
Usessulfur production, jewelry (marcasite), collector specimens, historical ignition source
Associated Mineralscalcite, quartz, dolomite, other sulfides
Rarityuncommon
Description
This specimen features several large, lustrous, well-formed cubic crystals of pyrite, exhibiting a brilliant metallic sheen, perched on a light-colored, rough matrix rock.
Geological Context
Pyrite forms in a wide range of geological environments, including hydrothermal veins, sedimentary rocks, and metamorphic rocks. The Navajún locality is famous for its exceptional cubic pyrite crystals found embedded in marl and limestone deposits.
