sedimentary

Weathered limestone fragment

Calcitic limestone, primarily calcium carbonate (CaCO₃; mineral calcite)

AI-generated identification · may be incorrect

Usually white, cream, or tan with a dull to earthy luster and irregular granular texture; calcite is Mohs 3, has rhombohedral cleavage, and reacts vigorously with dilute hydrochloric acid or vinegar. The specimen appears porous and weathered, possibly containing minor clay or iron-oxide staining.

Identified September 5, 2026More sedimentary →

Explore Weathered limestone fragment 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 accumulated marine shells, carbonate mud, or chemical precipitation, commonly during Paleozoic–Cenozoic sedimentary periods. Weathering and dissolution produced its rough, irregular surface.

Uses & applications

Used for aggregate, cement, lime, building stone, and soil neutralization; attractive varieties can be polished, though this fragment has little jewelry value.

Geological facts

Limestone commonly preserves fossils and karst features such as caves and sinkholes. Calcite’s acid reaction and relatively low hardness distinguish it from quartz-rich rocks.

Field identification & locations

Common worldwide in former shallow tropical seas, including the United States, Europe, and many parts of Asia. Identify it by its light color, softness, and acid fizz; a precise identification would require testing for fossils and acid reaction.