Yellow calcite (likely honey calcite)

Pale yellow, translucent to opaque, with a waxy-to-glassy luster and irregular cleavage surfaces; Mohs hardness 3, rhombohedral crystal structure, and specific gravity about 2.71.

Forms when calcium-rich groundwater precipitates carbonate in veins, cavities, caves, and sedimentary environments; specimens may range from ancient to geologically young, depending on the deposit.

Used for cement, lime, agricultural soil treatment, and decorative stone; attractive translucent pieces are collected, though this rough specimen has modest commercial value.

Calcite effervesces readily in dilute hydrochloric acid and can scratch or be scratched by common household materials because of its low hardness.

Common in limestone, marble, hydrothermal veins, and geodes worldwide, including Mexico, the United States, Brazil, and Iceland. Confirm with an acid test, rhombohedral cleavage, and hardness testing; the photograph alone cannot exclude yellow aragonite or weathered sulfur.