sedimentary

Fossiliferous limestone

Bioclastic limestone, primarily calcite (CaCO₃)

AI-generated identification · may be incorrect

Typically pale gray to tan, porous, and earthy to weakly crystalline, with visible shell fragments and cavities; calcite has Mohs hardness 3, vitreous to dull luster, rhombohedral cleavage, and specific gravity about 2.7. It effervesces strongly with dilute hydrochloric acid.

Identified September 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from accumulated marine shells and skeletal debris that lithified as carbonate sediment, commonly during the Paleozoic–Cenozoic eras. The holes may reflect dissolved fossils, burrows, or later weathering.

Uses & applications

Used as decorative stone, aggregate, cement and lime feedstock, and educational or fossil-collecting specimens; this irregular piece is mainly of collector interest.

Geological facts

The specimen visibly contains fossil shell material, likely molluscan or other marine invertebrate remains, preserved in a calcitic matrix.

Field identification & locations

Common in former shallow-marine basins worldwide, including limestone formations in Europe, North America, and the Middle East. Identify it by abundant fossil fragments, low hardness, porous texture, and acid reaction; avoid assuming every cavity is a fossil.