sedimentary
Fossil Coral (Pleurodictyum)
Pleurodictyum sp. (Order Tabulata)
Hardness: 3-4 (Calcite/Silica); Color: Tan, brown, and grey; Luster: Dull to earthy; Structure: Honeycomb-like or geometric corallites separated by dark walls.
- Hardness
- 3-4 (Calcite/Silica)
- Color
- Tan, brown, and grey
- Luster
- Dull to earthy
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Physical properties
Hardness: 3-4 (Calcite/Silica); Color: Tan, brown, and grey; Luster: Dull to earthy; Structure: Honeycomb-like or geometric corallites separated by dark walls.
Formation & geological history
Formed as a marine colony during the Devonian period (approx. 360-410 million years ago) in shallow subtropical seas that once covered the Ohio River Valley.
Uses & applications
Primarily used for geological study, paleontological collecting, and educational purposes. Some agatized specimens are used in lapidary art.
Geological facts
The location provided (near Louisville, KY) is world-famous for the Falls of the Ohio, one of the largest exposed Devonian fossil beds in the world. These corals lived in warm, shallow seas long before the age of dinosaurs.
Field identification & locations
Look for the distinctive 'honeycomb' or 'waffle' pattern of individual coral cells (corallites). Field identification is common in limestone outcrops and riverbeds in the Kentucky/Indiana region.
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