sedimentary
Favosites (Fossil Coral)
Favosites (Extinct Tabulate Coral)
Hardness: 3-4 (calcite) to 7 (if silicified); Color: Gray, tan, or white; Luster: Dull to earthy; Structure: Honeycomb-like hexagonal pores (corallites); Cleavage: None.
- Hardness
- 3-4 (calcite) to 7 (if silicified)
- Color
- Gray, tan, or white
- Luster
- Dull to earthy
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Physical properties
Hardness: 3-4 (calcite) to 7 (if silicified); Color: Gray, tan, or white; Luster: Dull to earthy; Structure: Honeycomb-like hexagonal pores (corallites); Cleavage: None.
Formation & geological history
Formed during the Silurian to Devonian periods (approx. 419-358 million years ago) in shallow, warm marine reef environments through the permineralization of coral skeletons.
Uses & applications
Scientific study, educational collections, decorative display, and lapidary use (cabochon cutting when silicified).
Geological facts
Commonly known as 'Honeycombed Coral' due to its distinct geometric pattern. Favosites corals lacked the septa (internal walls) found in modern corals, possessing instead 'tabulae' or horizontal floors within their tubes.
Field identification & locations
Identify by looking for the 'honeycomb' grid pattern on the surface of rounded stream or beach stones. Frequently found in the Great Lakes region (USA/Canada) and limestone quarries.
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