This is a small thumbnail of copper and calcite. It's from the Keweenaw Peninsula in Michigan. I think it's probably from the Quincy Mine, but I'm not an expert and don't know for sure. The label just said Keweenaw Peninsula, Michigan. It's a thumbnail, but it's got a very exceptionally clear calcite, and you can see the copper there at the base of the calcite. The bottom of the calcite is cleaved, but the calcite is really in great shape all the way around. So this would make actually a beautiful thumbnail specimen for somebody, and it is a calcite with a copper inclusion from Michigan.