mineral

Unidentified pale yellow mineral, likely calcite

Calcite (CaCO₃), provisional identification

AI-generated identification · may be incorrect

Pale yellow, translucent, glassy to pearly luster, irregular cleavage surfaces; calcite has Mohs hardness 3, rhombohedral crystal structure, and specific gravity about 2.71. The image is insufficient to confirm crystal form or distinguish it from gypsum or quartz.

Identified August 23, 2026More mineral →

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Physical properties

Formation & geological history

Calcite commonly forms in sedimentary limestone, hydrothermal veins, cavities, and geodes; deposits range from ancient to modern geological ages. Yellow coloration may result from iron or other impurities.

Uses & applications

Used in cement, lime, aggregate, agricultural soil treatment, and chemical manufacture; transparent crystals are collector specimens. This small rough piece has minimal commercial value.

Geological facts

Calcite effervesces vigorously with dilute hydrochloric acid or strong vinegar, unlike quartz and most gypsum. It shows distinctive rhombohedral cleavage and may display double refraction when clear.

Field identification & locations

Common worldwide, especially in limestone regions and hydrothermal mineral districts. Confirm with a steel knife or copper coin (calcite scratches easily) and an acid test; avoid destructive testing on valuable specimens.