sedimentary

Honeycomb Coral Fossil (Favosites)

Favosites alpenensis

Hardness: 3-4 (calcite) or 6.5-7 (if silicified); Color: Tan, gray, or white; Luster: Dull to earthy; Structure: Composed of small, hexagonal tubes (corallites) resembling a honeycomb; Composition: Calcium carbonate or Silica (chalcedony/chert).

Hardness: 3-4 (calcite) or 6
Color: Tan, gray, or white
Luster: Dull to earthy

Identified June 26, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the fossilization of extinct tabulate coral colonies from the Silurian to Devonian periods (approx. 419 to 358 million years ago) in shallow, warm marine environments.

Uses & applications

Used primarily as decorative collector specimens, educational materials for paleontology, and occasionally polished for lapidary work or unique jewelry settings.

Geological facts

Favosites were colonial corals that lived alongside trilobites and brachiopods. They went extinct during the Permian-Triassic extinction event. The walls between corallites were pierced by small pores called mural pores, which allowed nutrients to flow between individuals.

Field identification & locations

Identify by looking for a 'honeycomb' grid pattern on the surface. Commonly found in limestone quarries and along lake shores in the Great Lakes region (Michigan, Ohio, New York) and Ontario, Canada.

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