mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Sky blue to pale blue; Luster: Vitreous to waxy; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific Gravity: 2.71

Hardness: 3 on Mohs scale
Color: Sky blue to pale blue
Luster: Vitreous to waxy

Identified April 28, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3 on Mohs scale; Color: Sky blue to pale blue; Luster: Vitreous to waxy; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific Gravity: 2.71

Formation & geological history

Formed in sedimentary environments through chemical precipitation from calcium-rich waters, or in metamorphic marble deposits. It is commonly associated with limestone and marble formations across various geological eras.

Uses & applications

Primarily used as a decorative stone, in lapidary work for cabochons and carvings, and as a popular specimen for mineral collectors. Industrially, calcite is used in cement and lime production.

Geological facts

Blue Calcite is often referred to as a 'stone of the mind' in metaphysical circles. It is unique among calcites for its soft blue hue, which is caused by the inclusion of various metal ions during formation.

Field identification & locations

Identify by its sky-blue color, characteristic waxy luster, and its reaction (effervescence) when touched by a drop of dilute hydrochloric acid. It is very soft and can be scratched by a copper penny. Common locations include Mexico, Madagascar, and Brazil.