sedimentary
Fossil Coral (Honeycomb Coral)
Favosites (extinct genus of Tabulate coral)
Hardness: 3-4 (calcite base); Color: Tan, brown, or grayish-white; Luster: Dull to earthy; Structure: Hexagonal or polygonal 'cells' (corallites) creating a honeycomb appearance; Cleavage: None (fractures along fossil boundaries).
- Hardness
- 3-4 (calcite base)
- Color
- Tan, brown, or grayish-white
- Luster
- Dull to earthy
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Physical properties
Hardness: 3-4 (calcite base); Color: Tan, brown, or grayish-white; Luster: Dull to earthy; Structure: Hexagonal or polygonal 'cells' (corallites) creating a honeycomb appearance; Cleavage: None (fractures along fossil boundaries).
Formation & geological history
Formed through the fossilization of marine organisms in warm, shallow sunlit seas during the Ordovician to Devonian periods (approx. 488 to 359 million years ago). The organic structure was replaced by calcium carbonate (calcite) or silica.
Uses & applications
Used primarily as decorative specimens for collectors, educational tools in paleontology, and occasionally carved into jewelry or used in landscaping and masonry if found in large blocks of limestone.
Geological facts
Favosites are known as 'Honeycomb Corals' because the closely packed polygonal cells resemble a bee's nest. They were colonial animals, and the small holes on the walls (mural pores) allowed nutrients to be shared between individual polyps.
Field identification & locations
Identify in the field by looking for a geometric, hexagonal grid pattern on the rock surface, often found in limestone outcrops or gravel pits in formerly marine regions. Common in the Great Lakes region of North America and parts of Europe.
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