Major Specimen Localities, Part IV: Copper From Cornwall To Upper Michigan

This is a superb example of very well crystallized native copper from Michigan’s Upper Peninsula.

- Bob Jones

German silver miners were brought to Cornwall, England, to train farmers in the art of mining in the 1600s. I doubt they realized that the skills they taught to Cornish miners would spread all over the world. Using huge, steam-powered pumps to dewater mines and safe fuses to ignite gunpowder, Cornish miners—we call them Cousin Jacks—developed a host of mines here in America and in Mexico, Australia, and South America. German miners were brought to Cornwall when it was realized that the southwestern part of England was a very rich mineral province. Initial mining simply dug out the veins of copper, tin, lead, iron and arsenic that could be seen in the exposed cliffs overlooking the Atlantic Ocean.

By the 18th century, dozens of mine shafts had been sunk in Cornwall and neighboring Devon following these metal veins, which were rich in mineral species. These were not the usual copper species like azurite and malachite, but copper joined with arsenic and iron and lead to create a suite of minerals that included some new species.

England is an island nation and depends on a huge fleet of ships—wooden ships, in those days—to supply the nation with goods from all over the world and to protect the country from invasion. This was a time of worldwide exploration and colonization, and sailing ships were the means of doing it. The problem with wooden ships is that the wood has to be protected from creatures that burrow into it and weaken it. Enter sheets of copper, which were used to sheath the hulls for protection.