sedimentary

Tumbled limestone or dolostone pebble

Calcite-rich limestone (CaCO₃), possibly dolostone (CaMg(CO₃)₂)

AI-generated identification · may be incorrect

Creamy gray-beige, opaque, and finely granular with a matte-to-waxy luster; likely Mohs hardness 3–4, with no visible cleavage or crystals. It should fizz with dilute hydrochloric acid if calcitic limestone, while dolostone reacts weakly unless powdered.

Identified August 29, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from compacted carbonate mud, shells, or chemical precipitation in ancient marine settings, commonly Paleozoic to Mesozoic in age. Its rounded shape and smooth surface indicate stream or beach transport and/or tumbling.

Uses & applications

Used as aggregate, cement and lime feedstock, dimension stone, and landscaping material; attractive polished pieces are inexpensive curios or craft stones.

Geological facts

The mottled patches may represent fossil fragments, recrystallized carbonate, or iron/manganese staining. Image-only identification cannot reliably distinguish limestone from dolostone.

Field identification & locations

Common in limestone terrains, river gravels, and beaches; check for acid fizz, relatively low hardness, and a powdery white streak. A hand lens may reveal shell or fossil textures.