sedimentary

Fossilized Coral (Favosites)

Favosites (extinct genus of tabulate coral)

AI-generated identification · may be incorrect

Hardness: 3-4 (calcite) or up to 7 (if silicified). Color: Gray, tan, or white. Luster: Dull to earthy. Structure: Honeycomb-like pattern of hexagonal pores (corallites).

Hardness: 3-4 (calcite) or up to 7 (if silicified)
Color: Gray, tan, or white
Luster: Dull to earthy

Identified June 21, 2026More sedimentary →

Explore Fossilized Coral (Favosites) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3-4 (calcite) or up to 7 (if silicified). Color: Gray, tan, or white. Luster: Dull to earthy. Structure: Honeycomb-like pattern of hexagonal pores (corallites).

Formation & geological history

Formed through the replacement of organic coral structures with minerals (usually calcite or silica) in marine sedimentary environments during the Silurian to Devonian periods (approx. 430-360 million years ago).

Uses & applications

Primarily used as decorative display pieces, educational specimens, jewelry (when agatized), and as a component in limestone for construction.

Geological facts

Commonly known as 'Honeycomb Coral' due to its distinct geometric pattern. Unlike modern corals, these tabulate corals lacked the radiating septa (lines) within their pores.

Field identification & locations

Identify by looking for a repeating hexagonal or 'honeycomb' grid on the surface of a stony matrix. Commonly found in the Great Lakes region (e.g., Petoskey stones are a related type) and limestone quarries in the Midwest USA and UK.