sedimentary

Weathered limestone

Calcite-rich carbonate rock (mostly CaCO₃), possibly fossiliferous limestone

AI-generated identification · may be incorrect

Gray-brown, fine-grained, dull to earthy luster with a pale, weathered calcitic area. Typically Mohs hardness 3; weak-to-moderate reaction with dilute hydrochloric acid or vinegar, and no obvious cleavage in the massive rock.

Identified August 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from accumulated marine carbonate mud, shell debris, or reef material that lithified into limestone, commonly during the Mesozoic–Cenozoic. Weathering has produced the rounded, rough surface and lighter calcite-rich patch.

Uses & applications

Used as aggregate, road stone, cement and lime feedstock, building stone, and soil conditioner. This ordinary specimen has little commercial or jewelry value.

Geological facts

The image does not show diagnostic crystals or definite fossils, so marble, calcareous sandstone, or altered limestone remain possible. A concealed fossil fragment could explain the irregular pale patch.

Field identification & locations

Highly plausible near 17.2°N, 89.1°W, where extensive limestone and karst terrain occur in the Maya region of Belize/Guatemala. Confirm by placing a drop of vinegar on a fresh surface: vigorous fizz strongly supports limestone; a streak test and closer inspection may reveal fossils or sand grains.