The Keweenaw peninsula of northern Michigan has been mined for its abundant native copper since before 2000 B. C., but little is known about the early miners because only a few ancient tools and weapons have ever been found there. Nonetheless, it has been estimated that prehistoric people extracted more than four million pounds of copper from the area before their efforts ceased.
Mining of copper on a large scale did not resume until the 19th century, when thousands of mines opened in the region. In all of mining history, this deposit ranks as one of the greatest. For example, the Quincy “mine”, a series of mine shafts, smelters and mills, opened in 1848, and produced billions of pounds of copper in its 97 year history.
Unlike other copper deposits around the world which consist of a variety of copper-bearing minerals, the Keweenaw ore body consists of large concentrations of pure native copper. Most native copper occurs in massive, shapeless aggregates, but relatively rarely the metal forms sharp detailed crystals ranging in shape from simple cubes to incredibly complex twins. Thousands of stunning specimens of crystallized native copper have been produced by these mines.
