fossil

Fossil coral or stromatoporoid fragment

Likely fossilized colonial coral; exact taxon cannot be determined from the photograph

AI-generated identification · may be incorrect

Cream-pink, polished, opaque specimen with curved growth ridges, small cavities, and dull to slightly waxy luster; fossilized carbonate material is typically Mohs 3–4 and may effervesce weakly in dilute hydrochloric acid.

Identified September 4, 2026More fossil →

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Physical properties

Formation & geological history

A marine colonial organism accumulated calcium-carbonate skeletons that were later buried and mineralized, commonly during the Paleozoic or Mesozoic; polishing has exposed the growth structure.

Uses & applications

Used as a collectible fossil, educational specimen, or ornamental stone; generally not suitable for durable construction because it is soft and porous.

Geological facts

The repeated curved bands likely represent skeletal growth layers rather than mineral crystal faces; cavities may be original corallite or pore spaces.

Field identification & locations

Identify by branching or concentric skeletal textures and carbonate reaction; common fossil coral occurs in former shallow tropical seafloors, including parts of the United States, Morocco, Madagascar, and Indonesia.