🦴 Fossil facts
| Age | Devonian, about 350–400 million years old |
|---|---|
| Origin & sources | Lake Michigan and Lake Huron beaches in northern Lower Michigan, especially around Charlevoix, Petoskey and Alpena. |
| Composition | Calcite-replaced colonial coral (Favosites) in limestone |
How it forms
Favosites corals built mounds of tiny, tightly packed tubes in a warm Devonian sea that covered Michigan. Glaciers later broke up the limestone and spread the pebbles along the Great Lakes shores.
🌍 Where it's found
- Type locality
- Notable source / deposit
- Country of origin
Marker positions are approximate (region or locality level). Type localities from Wikidata; notable sources curated by Crystopedia.
Learn more
Fossil
Orange
RootThird Eye
Healing crystal
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