sedimentary

Weathered limestone fragment

Calcite-rich limestone, primarily calcium carbonate (CaCO₃)

AI-generated identification · may be incorrect

Pale cream to yellow, dull earthy luster, fine-grained and porous-looking with irregular fracture. Calcite hardness is Mohs 3; it should scratch easily with a steel knife and fizz strongly with dilute hydrochloric acid or vinegar (slower with vinegar).

Identified August 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from compacted carbonate mud or accumulated marine shells, then exposed and weathered. Limestone is common in Cretaceous–Cenozoic carbonate terrains around the Petén region of Guatemala, near 17.2°N, 89.1°W.

Uses & applications

Used for cement, lime, aggregate, road material, building stone, and soil neutralization; this small weathered piece has negligible commercial value.

Geological facts

The yellow coloration likely comes from iron-oxide staining or surface weathering. The image does not show diagnostic fossils or crystals, so identification is provisional.

Field identification & locations

The regional setting strongly supports limestone. Confirm with an acid-fizz test, low hardness, and a white powder streak; dolostone is a possible alternative but usually reacts weakly unless powdered.