🦴 Fossil facts
| Age | Ordovician to Permian, about 485–252 million years ago |
|---|---|
| Origin & sources | Worldwide. Classic sites include the Cincinnati area of Ohio, Indiana and Kentucky, the Falls of the Ohio, Morocco and Gotland (Sweden). |
| Composition | Calcite skeleton (rugose coral), often weathered out of limestone or shale |
How it forms
Rugose 'horn' corals lived alone on the seafloor, each polyp building a cone-shaped calcite cup with radiating walls. The group died out at the end of the Permian, and their sturdy cups survive in limestones.
🌍 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
Root
Healing crystal




