Celestine (or Celestite)

Physical Properties

Hardness: 3 – 3.5 (Mohs scale); Color: Pale blue, colorless, or white; Luster: Vitreous to pearly; Crystal structure: Orthorhombic; Cleavage: Perfect in one direction; Specific gravity: 3.9 – 4.0

Formation & Geological History

Usually forms in sedimentary rocks such as limestones and dolomites, often in cavities or geodes. It precipitates from strontium-rich hydrothermal fluids or evaporating seawater. Most specimens originate from the Phanerozoic eon.

Uses & Applications

Primary source of Strontium used in fireworks (red flames), flare guns, glass making, and metallurgy. Also highly valued by mineral collectors and used in metaphysical practices.

Geological Facts

The name 'Celestine' is derived from the Latin word 'caelestis,' meaning celestial or heavenly, referring to its typical sky-blue color. Madagascar is world-renowned for producing large celestine geodes.

Field Identification & Locations

Identify in the field by its high density (it feels heavier than'common' rocks of the same size), its soft surface that can be scratched by a copper coin, and its distinctive pale blue tabular or fibrous crystals.

Identified on: 4/19/2026

Mode: Standard