fossil

Honeycomb coral fossil

Fossilized colonial coral, likely tabulate coral (order Tabulata)

AI-generated identification · may be incorrect

Cream-to-golden yellow, porous honeycomb pattern of polygonal corallites, dull to waxy luster; calcite composition, Mohs hardness about 3–4, with no distinct cleavage. The visible structure is consistent with a silicified or calcitized coral fragment.

Identified September 8, 2026More fossil →

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Physical properties

Formation & geological history

A colonial marine coral skeleton was buried in carbonate sediment and mineralized during diagenesis, commonly during the Paleozoic Era (about 485–252 million years ago). Exact age and species require locality and microscopic examination.

Uses & applications

Primarily a fossil-collecting and educational specimen; polished coral is used decoratively and occasionally in jewelry. It has little industrial value as a small fragment.

Geological facts

The repeated cell pattern records the original coral colony and differs from ordinary limestone, which lacks organized corallite walls. Acid may fizz weakly if calcitic, while silicified specimens do not.

Field identification & locations

Identify by the tightly packed polygonal tubes or cells and golden limestone-like color; common in Paleozoic marine limestone deposits, especially the Great Lakes region, Australia, and parts of Europe. Avoid strong acid or scratching tests if preservation matters.