sedimentary

Small rounded limestone pebble

Limestone, predominantly calcite (CaCO₃), possibly fossiliferous or oolitic

AI-generated identification · may be incorrect

Light gray-beige, fine-grained, dull to slightly waxy surface with rounded weathering; calcite hardness Mohs 3, non-cleavage in aggregate, specific gravity about 2.7. Effervesces strongly with dilute hydrochloric acid or vinegar if fresh calcite is exposed.

Identified September 8, 2026More sedimentary →

Explore Small rounded limestone pebble 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

Formed from compacted carbonate mud, shell debris, or ooids in shallow marine environments; commonly Paleozoic–Cenozoic, though the specimen’s age cannot be determined visually. Its rounded shape indicates transport by water or abrasion.

Uses & applications

Used widely for cement, lime, aggregate, road base, soil treatment, and dimension stone; this small piece has minimal commercial value unless it contains an identifiable fossil or unusual texture.

Geological facts

Limestone is a sedimentary rock rather than a single mineral; recrystallization can convert it to marble. The apparent central texture may represent a fossil fragment, weathered inclusion, or iron-oxide staining.

Field identification & locations

Identify by its pale color, relatively soft surface, and acid reaction; it commonly occurs in stream gravels, beaches, quarries, and karst regions worldwide. A hand lens and acid test are useful, but the image alone cannot confirm a fossil.