fossil

Fossil coral (probable colonial/tabulate coral)

Fossilized coral; likely Tabulata or a scleractinian coral

AI-generated identification · may be incorrect

Pale cream, finely honeycombed surface with repeated corallite structures and layered interior; mainly calcite or original aragonite replaced by calcite. Mohs hardness about 3–4, dull to slightly waxy luster, no obvious cleavage, specific gravity roughly 2.6–2.8.

Identified September 10, 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 in Paleozoic–Cenozoic limestone deposits. The precise age cannot be determined from the photograph.

Uses & applications

Collected as a fossil and used for educational displays, lapidary items, and jewelry when stable and attractive; it is generally not a construction stone by itself.

Geological facts

The polygonal or maze-like pattern records individual coral animals (corallites), making it distinct from ordinary limestone. Acid may fizz because of its carbonate composition.

Field identification & locations

Look for repeating tiny tubes, honeycomb cells, or septa across broken and weathered surfaces; confirm with a dilute hydrochloric-acid test only on an inconspicuous spot. Common sources include fossiliferous limestones worldwide, especially Devonian and younger reef deposits.