Your Definitive Guide to Petoskey Stone Michigan's state stone is prized for its beautiful patterning, which is said to resemble the rays of the rising sun. Take an in-depth look at the famous fossilized coral--including a summary of the fascinating natural history, which began 400 million years ago. Learn all about it, and then head out and search for your own. Get expert advice from author Dan R. Lynch on how to identify and collect...