sedimentary
Fossilized Coral (Favosites)
Favosites goldfussi / Tabulata
Hardness: 3-4 (Calcite replacement) or 7 (Silicification), Color: Grey, tan, or white, Luster: Dull to earthy, Structure: Honeycomb-like hexagonal cells (corallites)
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Physical properties
Hardness: 3-4 (Calcite replacement) or 7 (Silicification), Color: Grey, tan, or white, Luster: Dull to earthy, Structure: Honeycomb-like hexagonal cells (corallites)
Formation & geological history
Formed in warm, shallow marine environments from the Ordovician to the Permian periods. These fossils are remains of extinct colonial corals where the skeleton was replaced by minerals like calcite or silica over millions of years.
Uses & applications
Educational tools, lapidary use for jewelry (when silicified like Petoskey stones), architectural stone, and geological collecting.
Geological facts
Often called Honeycomb Coral due to their hexagonal structure. They were major reef-builders before their extinction roughly 250 million years ago.
Field identification & locations
Identify in the field by the distinct tiny hexagonal pits across the surface. Commonly found in limestone beds, lakeshores (like the Great Lakes), and riverbeds in formerly marine regions.
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