Sterling silver, Petoskey stone ring with a square shank! It helps the ring from turning on the finger. Ring size is 61/2 with a solid section behind the stone, plus not a light weight, a solid ring all around. A nice oval Petoskey stone with 1 animal in the center of it. Petoskey stone was an animal when alive! Size of the Petoskey stone is about 1/2″ x 3/8″.