Lake Superior Copper District, Upper Peninsula, Michigan, USA

When large masses of Copper were discovered in the Michigan copper mines, to extract the copper, it had to be broken into pieces with chisels. This is because the Copper was mostly unaffected by blasting with dynamite. This was done at first with hand chisels and later with mechanized chisels. This specimen bears the marks of where a chisel penetrated the copper. It appears the specimen has some kind of coating on as it is shiny in places. Considering it was in a damp Michigan basement for 35 years, this would explain the slight amount of oxidation.

9.2 x 5.2 x 3.8 cm

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