sedimentary

Fossiliferous limestone

Bioclastic limestone, chiefly calcite (CaCO₃)

AI-generated identification · may be incorrect

Usually Mohs hardness 3, cream to tan, dull to mildly sugary luster, and variable porosity. The irregular cavities and shell-like textures suggest preserved marine fossils or dissolved fossil fragments; calcite commonly effervesces strongly in dilute hydrochloric acid.

Identified September 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when marine shells, skeletal debris, and carbonate mud accumulate, compact, and cement on shallow seafloors. The specimen’s exact geological age cannot be determined from the image, but such limestones range from Paleozoic to Recent.

Uses & applications

Used as aggregate, cement and lime feedstock, building stone, and decorative material; fossil-rich pieces are mainly collected or displayed. Typical small specimens have modest commercial value.

Geological facts

Its porous, fossil-textured appearance may also overlap with reef limestone or weathered calcarenite. Acid reaction and microscopic fossil identification are more reliable than appearance alone.

Field identification & locations

Common in former shallow-marine regions worldwide, including Europe, North America, the Middle East, and Southeast Asia. Look for visible shell fragments, low hardness, pale carbonate color, and vigorous acid fizzing; estimated value is about $5–$30 for an ordinary hand specimen, more if fossils are exceptionally preserved.