Native Copper in Basaltic Rock

Native copper is naturally formed metallic copper. In the Keweenaw Peninsula of Michigan, there is a large scale of native copper deposit along the basalt rock stripe (Stratigraphical layer) extending over 200 km. The copper was reduced from copper sulfides into metallic copper and embedded in the pores, cracks, and voids of basaltic rocks. From the cross section of the basalt rock, you can see the bright copper pieces.