sedimentary

Fossiliferous limestone

Bioclastic limestone, chiefly calcite (CaCO₃)

AI-generated identification · may be incorrect

Gray, fine- to coarse-grained, dull to weakly earthy luster, with visible shell or coral fragments and cavities; calcite hardness 3, non-cleaved to irregularly fractured, specific gravity about 2.6–2.8. Effervesces vigorously with dilute hydrochloric acid or vinegar, especially on fresh surfaces.

Identified August 29, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when marine shells, corals, and skeletal debris accumulate, compact, and cement on ancient seafloors; the exact age cannot be determined from the photograph and may range from Paleozoic to Cenozoic. The pale rounded inclusions are likely fossil fragments or molds.

Uses & applications

Used as crushed aggregate, roadstone, cement and lime feedstock, and occasionally as building or decorative stone; fossil-rich pieces are mainly collected for education and display.

Geological facts

Limestone can preserve abundant marine fossils and may develop caves or karst through dissolution by acidic groundwater.

Field identification & locations

Identify it by its gray carbonate matrix, embedded fossil textures, and acid reaction; common in former shallow-marine sedimentary basins worldwide. Exact fossil identification requires a closer, sharper view or broken surface.