sedimentary

Rounded light-colored cobble, likely limestone

Probable micritic limestone (calcite, CaCO₃); exact identification requires testing

AI-generated identification · may be incorrect

Pale gray-beige, dull, fine-grained and rounded, with a weathered, slightly porous surface. Limestone is mainly calcite (Mohs 3; trigonal crystal structure); the specimen’s hardness and cleavage cannot be confirmed visually.

Identified October 6, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed from accumulated carbonate mud or shell material, then lithified and rounded by transport in water. Its geological age and precise source cannot be determined from the image.

Uses & applications

Limestone is widely used for cement, lime, aggregate, and building stone; this small cobble is mainly suitable for collecting or landscaping.

Geological facts

A drop of dilute acid that fizzes supports a calcite-rich limestone identification; avoid testing valuable specimens without permission.

Field identification & locations

The smooth, rounded shape suggests abrasion in a stream, beach, or other transported setting. Limestone occurs worldwide, but a fresh broken surface or acid test is needed to distinguish it from other pale rocks.