sedimentary

Fossiliferous limestone

Bioclastic limestone, predominantly calcite (CaCO₃)

AI-generated identification · may be incorrect

Cream-colored, porous, and visibly layered with shell-like fossil fragments; calcite has Mohs hardness 3, vitreous to earthy luster, rhombohedral cleavage, and specific gravity about 2.7. It should effervesce strongly with dilute hydrochloric acid or vinegar.

Identified September 5, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from accumulated marine shells and skeletal debris that were compacted and cemented on an ancient seafloor, commonly during the Paleozoic–Cenozoic eras. The specimen appears weathered or naturally broken, exposing bedding and fossil material.

Uses & applications

Used as crushed stone, cement and lime feedstock, aggregate, and building stone; attractive fossiliferous pieces are collected or used decoratively. This small specimen has mainly educational or modest collector value.

Geological facts

The texture suggests bioclastic limestone, possibly coquina or a shell-rich limestone, but the photograph is insufficient for precise fossil or age identification. Acid testing and magnification would help distinguish it from calcitic sandstone or cemented shell material.

Field identification & locations

Common in former shallow-marine environments and limestone regions worldwide, including Florida, the Caribbean, Europe, and parts of North America. Look for abundant shell fragments, visible bedding, low hardness, and acid reaction; avoid confusing it with concrete.