Petoskey Stones

Best place to find them: Northern Michigan, particularly around the cities of Petoskey and Charlevoix, where the gray-and-white fossilized pieces of coral are abundant. Collectors have them polished to show off their pretty markings.

Why here: Millennia ago, warm, shallow seas covered Michigan’s Lower Peninsula, followed by glaciers that scraped the bedrock and deposited fossils along their paths. Each spring, Lake Michigan’s melting ice unearths new pieces and carries them to shore.

Don’t miss: Petoskey State Park, for camping, hiking, and lazing on the scenic bay beach. For more information call 800/447-2757, or visit michigan.gov/dnr.