sedimentary

Weathered limestone or calcitic cave deposit

Calcite (CaCO₃), likely porous limestone/travertine

AI-generated identification · may be incorrect

Cream to pale yellow, dull to waxy luster, irregular porous texture, and no visible crystal faces. Calcite has Mohs hardness 3, perfect rhombohedral cleavage, and specific gravity about 2.7; it effervesces strongly with dilute hydrochloric acid or vinegar, though vinegar may react slowly.

Identified August 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Most consistent with limestone altered by groundwater, possibly travertine or a small stalactitic/calcitic deposit. The image cannot establish geological age; such deposits may form from recent to ancient groundwater activity.

Uses & applications

Limestone is used for cement, aggregate, lime, and construction; decorative calcite and cave deposits are collected. This specimen appears low-grade and generally has little commercial value.

Geological facts

The knobbly, cream-colored surface suggests carbonate precipitation or weathering rather than a crystalline igneous rock. It is not possible to distinguish limestone, travertine, or calcite vein material confidently from the photograph alone.

Field identification & locations

The region near 17.2°N, 89.1°W in northern Guatemala is rich in Cretaceous limestone and karst terrain, making this identification geologically plausible. Test a fresh spot with dilute acid, inspect for fossils, and check whether a knife scratches it; avoid damaging a protected cave deposit.