Michigan Copper
Michigans Keweenaw is unique among copper-mining areas, because the copper is found in the form of pure copper metal deposits (native copper) instead of the copper oxides, sulfides or small copper flecks that form the copper ore at every other copper-mining district. Michigans copper was mined by Native Americans from the end of the Ice Age until they were displaced by European settlers. The copper even affected the borders of the United States, Benjamin Franklin, having heard of the copper deposits, made sure to include Isle Royale in our original borders.
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