Petoskey stones

I really enjoyed hunting for these stones in Lake Huron this summer. Wading into the cold water, scooping up a handful of rocks and sifting through them one by one. It wasn't until after I got back to SC and did a google that I realized that a Petoskey stone is actually fossilized coral.

Petoskey stones are mostly found in Lake Michigan, but we found these near Oscoda in Lake Huron. These are pretty small (1/4" -1") and are kept in a small water-filled spice jar. The patterns on the stones are more vivid when wet.
The one with the octagon shapes is the best... I named an afghan after it! :-)