sedimentary

Likely fossiliferous limestone

Micritic limestone, chiefly calcite (CaCO₃), possibly containing shell or coral fragments

AI-generated identification · may be incorrect

Typically white to cream, dull to weakly pearly, fine-grained and irregularly fractured; calcite hardness is 3, with indistinct cleavage and specific gravity around 2.7. The specimen appears porous and may preserve dissolved or broken fossil material.

Identified August 29, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms from accumulated carbonate mud and marine organisms in shallow seas, later compacted and cemented; age cannot be determined from the photograph and may range from Paleozoic to Cenozoic. The surrounding pieces could include weathered fossil limestone or reef debris.

Uses & applications

Used as aggregate, cement and lime feedstock, building stone, and architectural material; attractive fossiliferous pieces are sold for educational and decorative collecting. This small rough specimen generally has modest commercial value.

Geological facts

Calcite-rich limestone effervesces strongly with dilute hydrochloric acid or vinegar, although weathered surfaces may react weakly. Fossil fragments, bedding, and pore spaces are common diagnostic features.

Field identification & locations

Look for a pale color, low hardness, powdery texture, and vigorous acid fizz; avoid confusing it with quartz-rich rock, which does not fizz and is much harder. Common worldwide in former shallow-marine basins.