HUGE 21lb. Copper Piece

My friend found this beautiful piece of native copper in Central California in an old silver mine. The edges have been polished. Does this have any value for resale? Thanks.

More photos of the bottom and back side.

That didn't come "naturally" from California!!! Rather, that is a piece of glacial float copper from the Upper Peninsula of Michigan that has been buffed on one side to bring out the untarnished copper colour.

Thanks so much for the info!

The chances are that this is a specimen of copper from Michigan. If it were from California it would be quite surprising, and it is doubtful many people would believe it unless it could be confirmed that it did come from a mine in California and that would mean visiting the mine and finding more copper in place in the rocks of the mine by a reliable, knowledgeable person.

Rock Currier
Crystals not pistols.

If your friend insists that he/she did indeed collect it, ask for more info on how it was cut, and polished, and preserved from tarnishing.

The latter especially, the MI copper guys seem to have the process locked down better than anybody... it ain't simple.

A decent specimen of MI float copper, abundant on the market and sold by the pound.

Certainly has retail value, I'd say at least $100, maybe more. Lots of value just in the copper alone, assuming copper's still around four bucks a pound.