I have taken it to a few places and no one can tell me for sure what it is . A few guesses. 2 of the places sell and deal with minerals and gem specimen's.
I have one of those! both it and the large red granite one came from Southern Wisconsin...yes, its heavy...The Wife sees a 'cool' rock out in the Wild and she has me haul it home...All around the country I have been hauling 'cool' rocks for 40yrs! Even when we move, she makes me take the rocks along! They are fun to stack up...then they fall down, then you restack them, so its an ever changing piece of art...
We had a Garage/Moving sale last year, and some Lady pulled in, said she drives by our house every day from work and enjoys seeing the rock stack, says its the highlight of her day.
.....so guess what? She BOUGHT the whole stack for $700! The last time I had to lift those rocks was getting them into the back of her truck! Now, when me and the Wife are out, we sometimes drive past her place to see 'our' rocks!
Finally! I dont have to haul around heavy rocks anymore! I aint never seen a nickel of that money though...Wife said they were 'Her' rocks!
I've been showing Her your pictures of Big Copper...Her eyes take on a wild look, "Boy! Now THAT would make for a cool rock stack!"...so...I might have just freaked myself once again!
I suppose a fellow could solder large chunks of copper together so a guy only has to stack them once though! So theres that...