sedimentary

Favosites (Fossil Coral)

Favosites (Extinct Tabulate Coral)

AI-generated identification · may be incorrect

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

Identified June 20, 2026More sedimentary →

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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.