Mohawkite, a rare compound of silver, copper, arsenic, cobalt, nickel and iron, is found only in the Mohawk-Ahmeek area of Keweenaw County in Michigan. This 132 gram (4.6 ounce) nugget has been polished to show its pretty silvery tone with a hint of gold. A few years back we acquired the only available stash we know about of this material, which was mined in the 1950s. It had been sitting in a garage for a long, long time.