Large, 3.7" Polished Petoskey Stone (Fossil Coral) - Michigan
This is a beautiful piece of fossil coral (Hexagonaria percarinata) from Michigan. It has been polished to a glossy finish on the front, while the rest of the piece has only been polished to a matte finish. The polish really allows for the detailed structures of the coral head to be seen.
Known locally as "petoskey stones" this fossil coral can be found along the beaches of Lake Michigan, Lake Huron, as well as in rock quarries from Alpena to Traverse City, Michigan. The species is Hexagonaria percarinata, a type of rugose coral that lived during the Middle Devonian period, about 350 million years ago. Petoskey stones are the state stone of Michigan.