sedimentary

Likely weathered limestone or calcite-rich stone

Limestone, primarily calcium carbonate (CaCO₃), possibly calcite

AI-generated identification · may be incorrect

White to cream, dull to lightly waxy luster, irregular fracture, and no visible crystal structure; calcite has Mohs hardness 3 and specific gravity about 2.7. The specimen’s porous, crumbly appearance is consistent with weathered carbonate rock.

Identified August 11, 2026More sedimentary →

Explore Likely weathered limestone or calcite-rich stone 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 shells, carbonate mud, or precipitated calcium carbonate, commonly during the Paleozoic–Mesozoic; exact age cannot be determined from the image. Weathering or dissolution produced its uneven surface.

Uses & applications

Limestone is used for cement, aggregate, lime, building stone, and soil treatment; calcite-rich pieces are also collected, though this example appears low-grade.

Geological facts

A drop of dilute hydrochloric acid or vinegar may produce visible fizzing if fresh calcite is exposed, distinguishing it from most silicate rocks.

Field identification & locations

Common worldwide in former shallow-marine basins, including the United States, Europe, and the Middle East. Confirm by acid fizz, relatively low hardness, and a white streak; identification is provisional because the image lacks a scale and close texture detail.