sedimentary

Pale weathered pebble, likely limestone

Limestone, predominantly calcite (CaCO₃); exact identification is uncertain from the image

AI-generated identification · may be incorrect

Light tan, dull to weakly earthy luster, fine-grained and rounded from abrasion; calcite has Mohs hardness 3, rhombohedral cleavage, and specific gravity about 2.7. It may fizz with dilute hydrochloric acid or vinegar if fresh calcite is exposed.

Identified August 27, 2026More sedimentary →

Explore Pale weathered pebble, likely 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

Likely formed from compacted marine carbonate sediment and later rounded by stream, beach, or glacial transport; age cannot be determined visually and may range from recent to hundreds of millions of years.

Uses & applications

Commonly used for aggregate, cement, lime, building stone, and soil neutralization; this small ordinary pebble has little decorative or commercial value.

Geological facts

Limestone often contains microscopic fossils or shells, though none are visible here. Surface weathering can obscure its original texture and reduce the acid reaction.

Field identification & locations

Look for powdery pale surfaces, calcite grains or fossils, and effervescence in acid; distinguish it from quartzite, which is harder and will not fizz. Common worldwide, especially in former marine basins and river gravels.