fossil

Fossil coral (likely honeycomb or tabulate coral)

Fossilized colonial coral; possibly Favositidae (Favosites) or related tabulate coral

AI-generated identification · may be incorrect

Brown-gray, rounded and worn, with densely packed polygonal corallites. The original aragonite/calcite skeleton is mineral-replaced, commonly by silica or calcite; hardness is typically about 4–7, with dull to slightly waxy luster and no obvious cleavage.

Identified August 15, 2026More fossil →

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Physical properties

Formation & geological history

A marine colonial coral fossil formed when individual coral organisms secreted calcium-carbonate skeletons, later buried and lithified. Tabulate corals are mainly Paleozoic, especially Ordovician–Permian (roughly 485–252 million years old).

Uses & applications

Primarily a collectible and educational specimen; polished examples are used as decorative stone, cabochons, and jewelry. It has little industrial value.

Geological facts

The repeated honeycomb pattern represents individual coral chambers, not mineral crystals. Surface wear can obscure the walls between corallites, making it resemble weathered limestone.

Field identification & locations

Identify it by its regular microscopic-to-millimeter polygonal cells and solid stone texture; common sources include Paleozoic limestone regions of North America, Europe, and Australia. Acid testing is inadvisable because calcitic fossils may fizz and be damaged.