sedimentary

Tumbled fossiliferous limestone

Calcite-rich limestone (CaCO₃), possibly fossiliferous micrite

AI-generated identification · may be incorrect

Pale cream to gray-brown, earthy to waxy luster, rounded and polished; chiefly calcite, with visible porous fossil or shell fragments. Mohs hardness 3, non-cleavage to irregular fracture, specific gravity about 2.3–2.7; effervesces strongly with dilute hydrochloric acid.

Identified September 21, 2026More sedimentary →

Explore Tumbled 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 compacted and cemented marine carbonate mud, shells, and skeletal debris, commonly in shallow tropical seas. Its exact geologic age cannot be determined from the image; subsequent tumbling or polishing has rounded the specimen.

Uses & applications

Used as aggregate, cement and building/decorative stone; attractive fossiliferous pieces are collected or sold as polished curiosities, though this specimen appears modestly commercial.

Geological facts

The cavities and curved internal textures may represent dissolved shells, corals, or other carbonate fossils, but the image is insufficient for precise fossil identification.

Field identification & locations

Look for a soft, pale carbonate rock with fossil textures and acid fizz; it is commonly found in marine limestone regions worldwide. Estimated value: $5–$25 for a small polished specimen, potentially higher if a clearly identifiable fossil is exposed.