Chalcopyrite
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/14730981@N08">James Petts</a> from London, England (CC BY-SA 2.0)
Mineral NameChalcopyrite
Chemical FormulaCuFeS2
Mohs Hardness3.5
Crystal Systemtetragonal
Lustermetallic
Streak Colorgreenish-black
Cleavagepoor/indistinct
Fractureuneven to conchoidal
Specific Gravity4.2
Colorsbrass-yellow, golden-yellow, iridescent tarnish
Transparencyopaque
Type LocalityWidespread, found in numerous copper deposits globally
Mineral GroupSulfides
Usesmajor copper ore, collector specimens
Associated Mineralspyrite, sphalerite, galena, quartz, calcite
Raritycommon
Description
This specimen displays a brass-yellow, metallic mineral with patches of iridescent tarnish, embedded within a white crystalline matrix, likely quartz, and a darker grey host rock.
Geological Context
Chalcopyrite is the most important ore mineral of copper, typically forming in hydrothermal veins, porphyry copper deposits, and massive sulfide deposits, often in association with other sulfide minerals.
