Rock Identifier
Likely tumbled calcite or pale limestone fragment (Calcite (CaCO₃), possibly microcrystalline limestone) — mineral
mineral

Likely tumbled calcite or pale limestone fragment

Calcite (CaCO₃), possibly microcrystalline limestone

AI-generated identification · may be incorrect

Cream-white, opaque, irregularly rounded specimen with dull to slightly waxy luster. Calcite has Mohs hardness 3, rhombohedral cleavage, and specific gravity about 2.71; the image does not show diagnostic crystal faces.

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Physical properties

Cream-white, opaque, irregularly rounded specimen with dull to slightly waxy luster. Calcite has Mohs hardness 3, rhombohedral cleavage, and specific gravity about 2.71; the image does not show diagnostic crystal faces.

Formation & geological history

Calcite commonly forms in sedimentary limestones, caves, hydrothermal veins, and shells. The specimen appears naturally worn or manually tumbled; age cannot be determined from the photograph.

Uses & applications

Used in cement, lime, aggregate, soil treatment, and mineral collections. Attractive translucent pieces may be used as carving or decorative stone, but this example appears low-grade.

Geological facts

A drop of dilute hydrochloric acid or household vinegar may produce fizzing, especially on a freshly scratched surface; vinegar can be weak and inconclusive. It may also be a pale quartz-like pebble, though quartz is much harder and does not fizz.

Field identification & locations

The regional setting near 17.2°N, 89.1°W (northern Guatemala/southern Belize area) contains abundant limestone, making calcitic material plausible. Confirm with an acid test and hardness test: calcite scratches with a copper coin, while quartz scratches glass.