Chalcopyrite
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 3.0)
Mineral NameChalcopyrite
Chemical FormulaCuFeS2
Mohs Hardness3.5
Crystal Systemtetragonal
Lustermetallic
Streak Colorgreenish-black
Cleavagepoor/indistinct on {011}
Fractureuneven
Specific Gravity4.2
Colorsdark grey, purplish-blue, brassy yellow, iridescent
Transparencyopaque
Type LocalityRedruth, Cornwall, England
Mineral Groupsulfides
Usesmajor copper ore, collector
Associated Mineralspyrite, sphalerite, galena, quartz, calcite
Raritycommon
Description
This specimen of chalcopyrite exhibits a botryoidal (grape-like) form, displaying a dark, tarnished purplish-grey to iridescent blue color with a metallic luster, interspersed with patches of brassy yellow. The rounded aggregates create a textured surface.
Geological Context
Chalcopyrite is a common ore mineral found in a variety of geological settings, including hydrothermal veins, porphyry copper deposits, and volcanogenic massive sulfide (VMS) deposits, often forming at moderate to high temperatures.
