sedimentary
Fossil Coral (Favosites)
Favosites (Order: Tabulata, Phylum: Cnidaria)
Hardness: 3-4 (if calcite) or 7 (if silicified); Color: Tan, cream, or gray; Luster: Dull to waxy; Texture: Distinctive honeycomb structure consisting of small polygonal tubes (corallites).
- Hardness
- 3-4 (if calcite) or 7 (if silicified)
- Color
- Tan, cream, or gray
- Luster
- Dull to waxy
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Physical properties
Hardness: 3-4 (if calcite) or 7 (if silicified); Color: Tan, cream, or gray; Luster: Dull to waxy; Texture: Distinctive honeycomb structure consisting of small polygonal tubes (corallites).
Formation & geological history
Formed through the accumulation of colonial coral skeletons in shallow, warm marine environments during the Silurian to Devonian periods (approx. 419 to 358 million years ago). The organic matter is replaced by minerals like calcite or silica via permineralization.
Uses & applications
Used primarily as decorative collector specimens, educational fossils, and occasionally in jewelry (especially if petrified/agatized).
Geological facts
Known commonly as 'Honeycomb Coral' due to the regular hexagonal pattern of the corallites. These extinct corals lacked the septa (internal radiating walls) found in modern corals.
Field identification & locations
Identify by looking for the geometric 'honeycomb' pattern on the surface. Commonly found in the Great Lakes region of North America and other Paleozoic marine sedimentary basins. Collectors should look in limestone quarries or along rocky lake shores.
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