Also called copper pyrites, the most important copper
ore (CuFeS2), very similar to pyrite,
with which it is often associated in sulfide veins in igneous and certain
metamorphic rocks. The crystals are tetragonal but often occur in masses.
Hardness: 3.5–4; relative density 4.2. Clacopyrite is found in the
United States, Canada, Australia, western Europe, and South America.
Image source: Mineralogical Information Institute
AND PLANETARY SCIENCE