sedimentary
Fossilized Coral (Favosites)
Favosites (Extinct Tabulate Coral)
Hardness: 3-4 (calcite) or 6.5-7 (if silicified); Color: Tan, gray, or white; Luster: Dull to earthy; Structure: Honeycomb-like hexagonal cells (corallites).
- Hardness
- 3-4 (calcite) or 6
- Color
- Tan, gray, or white
- Luster
- Dull to earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-4 (calcite) or 6.5-7 (if silicified); Color: Tan, gray, or white; Luster: Dull to earthy; Structure: Honeycomb-like hexagonal cells (corallites).
Formation & geological history
Formed through the fossilization of ancient marine coral colonies, typically from the Silurian to Devonian periods (approx. 419-358 million years ago).
Uses & applications
Primarily used for geological education, fossil collecting, and occasionally as decorative stones or lapidary material when agatized.
Geological facts
Known as 'Honeycomb Coral' due to the regular pattern of the chambers where individual polyps lived; these corals were reef-builders in ancient shallow seas.
Field identification & locations
Identify by looking for the distinct 'honeycomb' grid pattern on the surface; commonly found in limestone-rich areas like the Great Lakes region or the Ohio River Valley.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary