Yellow Calcite

Mohs hardness of 3, vitreous to resinous luster, pale yellow to golden amber color, rhombohedral cleavage, trigonal crystal system, specific gravity ~2.71

Forms through chemical precipitation in sedimentary basins, hydrothermal veins, and hot springs, often associated with carbonatites or limestone deposits

Used as mineral specimens, lapidary carvings, tumbled stones for crystal collections, and historically in optical instruments

Calcite exhibits strong double refraction (birefringence), meaning light passing through the crystal splits into two rays, creating a double image when looking through transparent pieces

Identified by its softness (can be scratched by a copper coin or steel blade), perfect rhombohedral cleavage, and strong effervescence when exposed to cold dilute hydrochloric acid. Commonly found in Mexico, Brazil, USA, and Madagascar