Rock Identifier
Fossil coral (Fossilized colonial coral, likely honeycomb or branching coral (order Tabulata or Scleractinia); exact genus is indeterminate from the image) — fossil
fossil

Fossil coral

Fossilized colonial coral, likely honeycomb or branching coral (order Tabulata or Scleractinia); exact genus is indeterminate from the image

AI-generated identification · may be incorrect

Cream-colored, porous calcareous skeleton with repeated corallite pits; low luster, brittle, and mainly calcite or aragonite recrystallized to calcite. Mohs hardness is about 3–4; no obvious cleavage; specific gravity typically 2.6–2.8.

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Physical properties

Cream-colored, porous calcareous skeleton with repeated corallite pits; low luster, brittle, and mainly calcite or aragonite recrystallized to calcite. Mohs hardness is about 3–4; no obvious cleavage; specific gravity typically 2.6–2.8.

Formation & geological history

A colonial marine coral skeleton lithified and commonly permineralized or recrystallized during burial. Fossil corals range from Paleozoic to Cenozoic age; the exact age requires locality and microscopic identification.

Uses & applications

Used as a collectible fossil, educational specimen, and occasionally as decorative stone or jewelry after polishing; porous pieces are generally unsuitable for structural construction.

Geological facts

The holes are corallites—individual chambers occupied by coral polyps—not ordinary weathering cavities. Fossil coral is not the same as modern reef coral and may preserve distinctive honeycomb or septate patterns.

Field identification & locations

Identify it by regular repeated cups or tubes, carbonate composition, and marine-fossil texture; common in limestone deposits worldwide, especially Florida, the Caribbean, Europe, and parts of Asia. Vinegar may weakly fizz on a fresh surface.

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Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

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Fossiliferous limestone (likely a crinoidal or shell-fragment limestone) (Bioclastic limestone, composed chiefly of calcite (CaCO₃)) — sedimentary

Fossiliferous limestone (likely a crinoidal or shell-fragment limestone)

Bioclastic limestone, composed chiefly of calcite (CaCO₃)

sedimentary
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Porous limestone pebble

Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image

sedimentary
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Weathered fossil bone fragment (identification uncertain)

Fossilized bone; exact taxon and mineral composition cannot be determined from the image

fossil