sedimentary
Favosites Fossil (Honeycomb Coral Pebble)
Favosites goldfussi / Silicified Coral Fossil
Hardness: 6.5-7 (if silicified/replaced by quartz); Color: Gray, tan, or brown; Luster: Dull to waxy; Structure: Tabular, honeycomb-like pores (corallites); Specific gravity: 2.6-2.7.
- Hardness
- 6
- Color
- Gray, tan, or brown
- Luster
- Dull to waxy
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Physical properties
Hardness: 6.5-7 (if silicified/replaced by quartz); Color: Gray, tan, or brown; Luster: Dull to waxy; Structure: Tabular, honeycomb-like pores (corallites); Specific gravity: 2.6-2.7.
Formation & geological history
Formed during the Silurian to Devonian periods (approx. 400 million years ago) in warm, shallow marine environments. This specimen has been smoothed into a pebble by water erosion.
Uses & applications
Collecting, educational specimens, lapidary use (cabochons), and decorative garden stones.
Geological facts
Commonly known as Honeycomb Coral because of the hexagonal pattern of the individual coral polyps. These were colonial corals that lived long before the extinction of the dinosaurs.
Field identification & locations
Identify in the field by looking for a 'honeycomb' or grid-like pattern on the surface of smooth river or beach stones. Frequently found in the Great Lakes region and limestone outcrops.
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