sedimentary

Fossiliferous limestone

Bioclastic carbonate rock, chiefly calcite (CaCO₃), containing visible marine fossils

AI-generated identification · may be incorrect

Typically Mohs hardness 3, pale gray to buff, dull to earthy luster, fine-grained matrix, and no prominent cleavage; calcite may effervesce vigorously with dilute hydrochloric acid. The visible shell impressions and fragmentary fossil forms are diagnostic.

Identified August 30, 2026More sedimentary →

Explore Fossiliferous limestone in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms from accumulated, compacted, and cemented marine shells and carbonate mud in shallow-sea environments. Its precise age cannot be determined from the photograph; it may range from Paleozoic to Cenozoic depending on locality.

Uses & applications

Used as aggregate, cement and lime feedstock, building stone, and educational or decorative fossil material; well-preserved specimens have modest collector interest.

Geological facts

The fossils appear to include small brachiopod or bivalve-like shells, but precise identification requires clearer detail and locality information.

Field identification & locations

Identify it by its light color, carbonate texture, embedded fossils, and acid reaction; common in former shallow-marine sedimentary basins worldwide. Avoid prolonged acid exposure if preserving the fossils.