This specimen gives new meaning to the term "robust" in terms of copper crystal size. It is very impactful for the size, and has an unusual aesthetic compared to so many other old Michigan coppers. These crystals are big and fat, with a really nice rich patina that only comes on old, uncleaned pieces. (The first photos shows the best patina, as it was shot in normal room lighting - the others shot in halogen give it a more brassy look). It is crystallized ALL around and is complete with no damage. Ex. Columbia School of Mines collection, with a good old label showing that it was part of the major historic Columbia collection absorbed by the American Museum of Natural History in NYC in the past, and giving a specific and valued mine name. This would certainly be of pre-WWII vintage.