The MN State gem: Beautiful Lake Superior Agates - found on both north (MN) and south (WI) shores of Lake Superior. - Agates are semi precious stones so common on Lake Superior beaches no one pays much attention. #MSPdestination
Copper Replacement Agate cabachon : Many of the larger copper agates are too fractured from the mining process to cut a cabachon. This magnificent one wasn't. The dark inclusion in the upper center appears to be dense plumes of tenorite, the black copper oxide.