mineral

Yellow Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Pale yellow to deep golden; Luster: Vitreous to waxy; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific gravity: 2.71.

Hardness: 3 on Mohs scale
Color: Pale yellow to deep golden
Luster: Vitreous to waxy

Identified February 14, 2026More mineral →

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Physical properties

Formation & geological history

Formed through sedimentary processes such as precipitation from calcium-rich solutions in caves (forming stalactites/stalagmites) or through marine organism accumulation. It can also occur in hydrothermal veins.

Uses & applications

Used in the manufacturing of cement and mortar, as a flux in glassmaking, in the optical industry (due to double refraction), and frequently as decorative tumbled stones or 'well-being' crystals.

Geological facts

Calcite is famous for its optical property called double refraction; when you look through a clear piece, images appear doubled. It is the primary component of limestone and marble.

Field identification & locations

Identify in the field by its 3-way rhombohedral cleavage (it breaks into tilted cubes/blocks) and its reaction to weak acid, which causes it to effervesce or fizz. Common in limestone quarries and karst landscapes.