What element used to be mined in the upper peninsula of michigan? several towns in the upper peninsula are named after this element, including harbor.

Copper

Explanation:

The copper transition element is a discreet yellowish-red metal, with a slightly opaque gloss of pleasant appearance, a soft, malleable and ductile metal. The chemical symbol of the metal is Cu, originated from the Latin cuprum, alluding to the island of Cyprus where it is believed to have been found for the first time.

It is found in nature in the form of CuFeS2 chalcopyrite, mainly there are others, but this one has a higher content of the metal, besides being one of the metals that can be found in elemental state.

Copper used to be mined on the Upper Peninsula of Michigan. Several cities on this Peninsula are named after Copper, including Copper Harbor.