sedimentary

Fossiliferous limestone

Bioclastic carbonate rock, predominantly calcite (CaCO₃)

AI-generated identification · may be incorrect

Typically gray to cream, fine- to coarse-grained, with visible shell fragments and cavities; calcite has Mohs hardness 3, vitreous to earthy luster, rhombohedral cleavage, and specific gravity about 2.7. It fizzes vigorously with dilute hydrochloric acid.

Identified September 18, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when marine shells and skeletal debris accumulate, are compacted, and cemented on shallow seafloors; age depends on locality, commonly Paleozoic to Cenozoic. The image shows a weathered, fossil-bearing slab rather than a crystal specimen.

Uses & applications

Used as dimension stone, aggregate, cement and lime feedstock, and decorative or educational material; attractive polished pieces may be used ornamentally.

Geological facts

The pale inclusions are likely fossil fragments or ooids, while dark pores may reflect weathering or organic-rich sediment. Fossiliferous limestone records ancient marine ecosystems and water chemistry.

Field identification & locations

Look for identifiable shell textures, irregular bedding, and acid reaction; distinguish it from marble because fossils and sedimentary fabric are preserved. Common worldwide in former shallow-marine basins, including Europe, North America, and the Middle East.