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Saturdays attempt to identify rocks in the Great Lakes: Lightning Stones/ Septarian Stones

Updated: May 19, 2023

Good morning!

It's Saturday! A little identification and information on another local stone.

This one should be an easy pressure.

Lightning stones / Septarian stones.

Again, I am not an expert. If anyone wants to chime in to correct or help, please do.

These stones are concretions dating back 50 to 70 million years. When waters were higher. It is thought that volcanic eruptions or other environmental factors, killed off sea life and sank to the sea bed. Over decomposition and time. Sediments and decomposed matter created a mud ball or nodule.

As the water level decreased, These balls or nodules dried and cracked. The cracks filled in with calcite, argonite and barite. It actually has nothing to do with lightning.

These stones can be found mostly in the south west of the state. Grand Haven, Pilgrim Haven and Pier Cove beaches. They are fun to find. You never know what shape you will find.

Here are a few of my pics from our trip to Pier Cove and what we did with them.

Please feel free to post your own favorite lightning stone.

Have an Awesome day!

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