Someone on E-Bay is selling a 1840 pound chunk of float copper starting bid at 6000, buy it now at 8000....This is the interesting description he gave....Float copper first formed as vein copper in the cracks of basalt flows, most likely coming in as a hot solution from deep underground. As the hot solution cooled, very pure copper precipitated out. This mix of copper and rock sat there in place for a very long time until at least one of a series of many glaciers formed in what is now Michigan's Upper Peninsula (specifically the Keweenaw Peninsula). These glaciers tore out sections of copper and rock, crushing and tumbling them until the brittle rock fell away. This left very pure nuggets of copper strewn throughout the glacial deposits of the region (some of these nuggets have been found as far south as Ohio). These nuggets occur in sizes from tiny to huge (I think the largest found to date is around 80,000 pounds). The piece being sold in this auction is not quite that large, but it is rather large - 1840 pounds. It measures 63" x 44" x 4" thick. It has a green oxidation patina from weathering in the ground for who knows how long. It also has a couple knobs of native silver on it, making it a half-breed (not anywhere near half though). There are several obvious glacier scrape marks over the top surface as well.....I live in the Western end of the U.P. about 15 mile South of Lake Superior.
