fossil

Fossiliferous limestone

Bioclastic limestone, primarily calcite (CaCO₃), containing marine shell or coral fossils

AI-generated identification · may be incorrect

Usually Mohs 3, tan to gray, dull to weakly earthy luster, fine-grained carbonate matrix with visible fossil cavities and shell fragments; calcite shows rhombohedral cleavage and effervesces strongly in dilute hydrochloric acid.

Identified September 10, 2026More fossil →

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Physical properties

Formation & geological history

Formed from compacted and cemented marine skeletal debris in shallow seas, commonly during the Paleozoic or Mesozoic; the exact age cannot be determined from the photograph alone.

Uses & applications

Used as a building stone, aggregate, cement and lime feedstock; attractive polished pieces are sold as decorative or educational fossils, though this specimen appears moderately preserved.

Geological facts

The rounded cavities and curved internal structures likely represent dissolved or partially preserved shells, corals, or other marine organisms rather than igneous vesicles.

Field identification & locations

Identify it by abundant carbonate fossils, soft scratchability, and acid effervescence; common in former shallow-marine sedimentary basins worldwide, including Europe, North America, and the Middle East.