If you visit Northern Michigan, you can’t leave without taking home a Petoskey Stone souvenir.

The stones, fossilized coral which experts say were deposited by glaciers eons ago, are found only in Northern Michigan. You can identify the Petoskey Stone by the hexagon pattern that covers them. Each hexagon has a dark center radiating out to a white outline.

Every year, locals, as well as visitors, comb the beaches looking for the unusual stones. Old-timers talk about once finding Petoskey Stones by the buckets full at Lake Michigan beaches. These days it takes a little more hunting to find the stones, now that the easy pickings have been gleaned from most beaches. That doesn’t mean you can’t still find them. You just have to know when and where to look.

Petoskey Stone Hunting Tips:

1. What you need: You don’t need a lot of specialized equipment to find Petoskey stones. A small spade, something to carry your found treasures, and, most importantly, a water bottle. A lot of Petoskey stones are found near the waterline, and they’re already wet. If you do come across a dry one, it will look like just another limestone rock. The pattern doesn’t show unless the stone is wet or polished. So if you think you found one, but it’s dry, test it by sprinkling it with water. If the familiar hexagon pattern appears, you have a Petoskey Stone.

2. Rocky beaches are obvious places to look for the stones. You’ll have better luck at small, roadside beaches, rather than the popular parks where everyone likes to swim and sunbathe.

3. You’ll find the stones other places besides right at the waterline. Try digging down into the sand beyond where the water comes up on shore. Many beaches are also lined with steep, tree-covered hills. Scour the hills. Look in loose dirt surrounding any trees that may have been uprooted. These are areas where the average hunter just doesn’t think to look.

4. Another often overlooked place to search for the stones is in the water, 10 to 15 feet out from shore. If you do this. you may need some special equipment. Snorkel gear will come in handy and a wetsuit will keep you warm, depending on water temperatures and the time of year.

5. Not all Petoskey Stones are found right at the beach. They sometimes turn up in the dirt along roadbeds, in gravel pits and freshly plowed farm fields. Just be sure you aren’t trespassing on private property.

6. If you find one Petoskey Stone, keep looking. They’re often found in clusters.

7. Certain times are better than others for finding the stones. Winter ice drags the stones up on shore, so early spring after the thaw is a good time to look. In the spring, you’ll also beat all the summer tourists to the hunt. Fall winds kick up big waves that throw Petoskey stones up on the shore. Another good time to search is after a summer thunderstorm that creates big waves.

8. If you come across a large cache of Petoskey Stones, don’t take too many. A state law says that one person can’t remove more the 25 lbs. of rock or mineral from state lands at one time. A year ago, a man found a 93 lb. Petoskey Stone. The State took it back after finding out about it through social media. The water of Lake Michigan and the land under it, along Michigan shoreline, are under state jurisdiction, even if it abuts to private property.

9. If your hunt for Petoskey Stones is unsuccessful, you don’t have to go home empty-handed. You’ll find the stones for sale in Northern Michigan shops like Grandpa Shorter’s. They’ll even come already polished, so you don’t have to keep spraying them with water just to see the unique pattern. You can also purchase jewelry made with the stones and wear a piece of Michigan wherever you go.