mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Pale blue to sky blue; Luster: Vitreous to pearly; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific gravity: 2.71.

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

Identified April 30, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed through sedimentary processes, often by chemical precipitation in marine environments or through hydrothermal activity. It is common in limestone and marble formations of various geological ages.

Uses & applications

Used primarily as decorative carvings, lapidary slabs, and as a popular specimen for metaphysical and mineral collectors. Industrial uses of calcite include cement, lime, and as a soil neutralizer.

Geological facts

Blue calcite is particularly known for its 'waxy' texture when handled. It is acid-sensitive and will effervesce (fizz) if a drop of weak hydrochloric acid or vinegar is applied to it.

Field identification & locations

Identify by its softness (can be scratched by a copper penny) and its distinct rhombohedral cleavage. Commonly found in Madagascar, Mexico, and Brazil. Collectors look for deep color and translucency.