Tips for finding and polishing Petoskey stones

(WJBK) - Petoskey stones are Michigan's geological claim to fame. The stones, which became the state stone in 1965, are fossilized coral that are millions of years old. They're unique to the Great Lakes and can be found along the shores of Michigan's lower peninsula. 

But do you know exactly where to find one? Or what to do with it if you see one? Diane Stampfler with Promote Michigan joined us on The Nine with some tips for your Petoskey stone hunt. 

"What is is, is the skeleton of the fossil," she says. "So the dead remains of the fossil. And it creates this beautiful hexagon pattern. What's unique is every one is different, kind of like a snowflake."

She says April and May is the easiest time to find them, as they've been churning around the water during winter. After a big storm is another prime hunting time. 

Some of the recommended places to go are Petoskey State Park; near the breakwall in Petoskey; Magnus City Park Beach; and along Lake Michigan in Petoskey and Charlevoix.

The pattern can sometimes be hard to spot, so you may be walking along the stones and not even realize it. Stampfler says the patten is more noticeable when the rocks are wet, so you could try dipping some rocks in the water or take along a squirt bottle. 

If you do find stones they'll need to be polished, which will take a little bit of grunt work. Stampfler says start with the highest grade sandpaper and work in a circular pattern, all the way down to the lower grade paper. A little bit of clear nail polish will give it a nice shine, too. 

"If you sit on the couch and watch TV with a towel on your lap, you can kind of just do this aimlessly," she says. "Polish until it gets smooth and you go down until the next grade, next grade, and at the very end it will be polished." She says it will take a long time, and about four different grades of sandpaper. She also warns not to put the stones in a sand tumbler -- because you'll end up with a pile of sand, not a polished rock. 

Polished Petoskey stones are valuable, and you can find them in jewelry or picture frames. 

There is a limit, though, on how much you can collect. Stampfler tell us the state limit is 25 lbs. per year. She says, too, that a man found one once that weighed 92 lbs. and that it was confiscated by the state.