Vacation Research Petoskey Stones

I've been doing research on Michigan and it seems that there are some special stones  found only in Michigan. It's not the same as hunting sea shells, but I think I'm up for it.

The Petoskey Stone is a type of fossilized colony coral found only in Michigan, the coral living during the Devonian period about 350 million years ago when Michigan had a warm inland sea. Because of the "eye" type configurations it shows especially when polished, it is said to mystically help stimulate the third eye and psychic awareness. Petoskey Stone is also said to keep naughty spirits from channeling incorrect information or interfering with one's life. In particular, as far as awareness, Petoskey Stone is said to enhance awareness of the emotions, which can be a boon for dealing with emotional issues. It is also said to clear out negative energies from the aura and the environment. Traditional healing folklore and crystal healing lore purport that Petoskey Stone is helpful for healing AIDS, Cancer, CFS, eyes, head, infections, infectious disease, lungs, skeletal system, and tumors of all kinds. Petoskey Stone is related primarily to the third eye chakra as well as the crown chakra.

From trip advisor:

It's getting harder and harder to find good petoskey stones, especially at the popular beaches. To find them in the wild, you'll have to scour the beaches (Petoskey stones can be found anywhere in Northern Michigan, but stony Lake Michigan beaches seem to be the best spot to look). If you're in town, avoid the Bayfront Park, this will be pretty well picked over. Just south, is Magnus Park which might be a good spot to start. Also, if you take 31 South there are several small roadside parks between Petoskey and Charlevoix that would be good places to look.
Here's a picture of a live Petoskey Stone

I'm sure the water will be a little too cool to actually find one in the water, but aren't they neat looking?

Now here's what I want to look for: