sedimentary

Fossiliferous limestone

Bioclastic limestone, composed chiefly of calcite (CaCO₃) and fossil fragments

AI-generated identification · may be incorrect

Gray-white, rough and weathered, with abundant pale shell or coral-like fragments in a fine carbonate matrix; calcite hardness 3 Mohs, generally dull to slightly crystalline. The rounded form appears naturally water-worn; exact fossil and mineral identification needs close inspection.

Identified October 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Marine organisms accumulated on an ancient seafloor and were buried, compacted, and cemented into limestone. Limestone spans many geological ages, so the specimen’s age cannot be determined from the photo.

Uses & applications

Limestone is widely used for cement, lime, aggregate, and building stone; fossil-rich pieces are mainly collected or used decoratively.

Geological facts

Calcite-rich limestone typically fizzes when exposed to dilute acid, though weathering or coatings can reduce the reaction.

Field identification & locations

Look for recognizable shell or skeletal fragments and test a fresh spot with dilute acid; common in sedimentary formations worldwide. The image suggests a fossil-rich limestone cobble, but does not show enough detail to identify specific fossils.