sedimentary

Likely limestone

Calcite-rich limestone (primarily CaCO₃); identification from the photo is tentative

AI-generated identification · may be incorrect

Pale gray-beige, dull, fine-grained and unevenly fractured, with possible small fossil or mineral specks. Calcite is Mohs 3 and reacts with dilute acid; crystal structure is trigonal, but the rock’s texture is not clear enough here to confirm limestone.

Identified September 22, 2026More sedimentary →

Explore 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

Limestone forms by accumulation and lithification of carbonate mud, shells, or other calcium-carbonate material, commonly in marine settings. Its age cannot be determined from the photograph.

Uses & applications

Used as building and aggregate stone, cement and lime feedstock, and occasionally as a decorative or collectible specimen.

Geological facts

The specimen’s irregular, weathered surface and pale color fit limestone, but are not diagnostic; other pale sedimentary rocks could look similar.

Field identification & locations

A hand-lens view, scratch test, and dilute-acid fizz test on a fresh surface can help distinguish limestone from sandstone or other rocks. The reported central-Iran location makes sedimentary carbonate plausible, but does not establish provenance.