Search for Michigan's state stone on Lake Michigan beaches near Petoskey and Charlevoix. Fossilized coral, 350 million years old, free for the finding.
Free
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The Petoskey stone is fossilized coral, Hexagonaria percarinata, roughly 350 million years old and Michigan's state stone. The hexagonal pattern only shows when wet, so the search happens along the waterline on Lake Michigan beaches near Petoskey and Charlevoix.
No equipment, no guide, no booking, no cost. You walk the beach, pick up stones, and turn them in the light or dip them in the lake. Beaches near Magnus Park in Petoskey and North Point Nature Preserve in Charlevoix are productive. Conditions are best after storms or spring thaw, when wave action exposes fresh material from the lake bottom. It fills an hour or two between a round and dinner, or keeps a travelling companion occupied while you're on the course. A found Petoskey stone, polished or raw, is the best souvenir a Northern Michigan trip can produce.
Wet the stone to see the pattern; dry Petoskey stones are hard to tell from ordinary rock. Beaches with mixed gravel and stone are more productive than pure sand. Many visitors carry a small spray bottle to test stones without walking back to the water each time. Free, year-round, no permit required.