mineral

Blue Calcite Sphere

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Pale blue to sky blue; Luster: Vitreous to waxy; Crystal Structure: Trigonal (often massive in spheres); Cleavage: Perfect rhombohedral; Specific Gravity: 2.71

Hardness: 3 on Mohs scale
Color: Pale blue to sky blue
Luster: Vitreous to waxy

Identified July 7, 2026More mineral →

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Physical properties

Hardness: 3 on Mohs scale; Color: Pale blue to sky blue; Luster: Vitreous to waxy; Crystal Structure: Trigonal (often massive in spheres); Cleavage: Perfect rhombohedral; Specific Gravity: 2.71

Formation & geological history

Formed through sedimentary processes or as a secondary mineral in igneous environments. It often precipitates from calcium-rich hydrothermal fluids or forms in large masses within limestone deposits. Major deposits are found in Mexico and Madagascar.

Uses & applications

Primarily used as a decorative specimen, for metaphysical collecting, or as a source of calcium in various industrial chemical processes.

Geological facts

Calcite is one of the most common minerals on Earth, but the soft blue variety is prized for its calming hue. It is double-refractive, meaning light splitting through a clear crystal creates a double image.

Field identification & locations

Can be identified by its softness (can be scratched by a copper coin) and its reaction to dilute hydrochloric acid (it will fizz). Commonly found in rock shops as spheres, hearts, or tumbled stones.