Rock & Fossil Hunting in Southwest Michigan

Michigan’s shoreline is an amazing place to find rocks because there are a wealth of beautiful stones and plenty of parks and beaches from which to access Lake Michigan. So bring a bucket big enough for your findings, and come rock and fossil hunting in Southwest Michigan!

Rocks and fossils you can find on the shores of Lake Michigan

Rockhounding is a very personal experience as it differs based on what people find appealing to collect. Do you like stones with holes, patterns or concretions? Maybe a mix of all of those suits you. Here’s what to keep an eye out for when you’re pacing the shoreline looking for those treasures.

Crinoids

These fossils were part of the stems section of an animal that is a distant relative of the starfish. They look like small disks, and often have a hole through them. Crinoids are quite abundant in the area and are a popular item for handmade jewelry!

Favosites

Also called Honeycomb Corals, these fossils consist of closely grouped calcitic tubes that resemble honeycomb. The pattern is much smaller than that of a Petoskey Stone and looks more like lace.

Fossiliferous Limestone 

These stones contain an abundance of fossils such as the shells of mollusks, crinoids and other organisms. Though these stones are not necessarily pretty when you find them, they can be quite stunning when cut and polished. 

Geodes 

A rare and exciting find, these rounded rock structures have a sparkling internal cavity lined with crystals. They are formed when minerals crystallize inside hollow cavities in stone. Geodes can be found in a variety of colors and mineral compositions.

Halysites 

Find these fossilized corals by looking for something similar to interlocking strings of tiny chains.

Petoskey Stones 

Yes, you can find Petoskey Stones in Southwest Michigan, if you’re lucky! The official state stone is easy to identify, especially when wet. These fossils consist of tightly-packed, six-sided corallites and have thin lines radiating out from a darker center.

Rugosa

You’ll know when you’ve found one of these “horn corals.” Look for pieces of fossilized coral with a unique horn-like shape.

Sandstone 

Look for layering in different colors or different patterns of color to identify one of these sedimentary stones. Sandstone can come in a variety of colors!

Septarian Nodules

Better known as “lightning stones'' or “turtle stones,” these unique stones are found at a variety of beaches in Southwest Michigan. They were formed from iron-rich mud and clay that cracked. Those cracks filled with calcite. The result is a fascinating stone that has a craquelure or lightning-like pattern of lighter color lines on a darker background.

Uniquely shaped rocks

If you use your imagination, the beach is full of interesting potential. Find stones that look like states, letters, fruits, hearts and much more. 

Tips for rock hunting: 

• Look for locations that are less popular so that there is less competition.
• Avoid maintained beaches because stones may be removed as part of cleaning. 
• Be prepared to walk. Southwest Michigan has a sporadically-rocky shoreline, and you may have to walk some distance between rocky sections.  
• Look closely. There are many beautiful, but tiny, stones and fossils. 
• Go out after wind storms. Waves on the lake move a lot of stone and push it up onto the shoreline. Wind storms can drastically change the shoreline, removing sections of stone and creating new ones in other areas, too. This is why spring and late fall are two of the best times to rockhound.
• Hunt after rain. It is a lot easier to identify stones when they are wet!
• Bring a bucket or bag to collect your finds. 

While hunting for stones, be on the lookout for beach glass, smoothed bits of ceramic and slag. Although these are man-made garbage, over time, the lake will smooth them, making them beautiful collectibles. 

Important note: While out rock hunting please keep in mind that it is illegal to remove stones from a National Shoreline, and that there are limits to the amount you can collect from State Parks (DNR rules).

While you are out rockhounding, carry a garbage bag in order to dispose of garbage you find along the shore. Always strive to make the shoreline even prettier than you found it!

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