mineral

Blue Celestine

Celestine (SrSO4)

Hardness: 3 to 3.5 on the Mohs scale; Color: Pale blue, white, colorless, or slightly tinted yellow/red; Luster: Vitreous to pearly; Crystal structure: Orthorhombic; Cleavage: Perfect on {001}, distinct on {210}, poor on {010}; Specific gravity: 3.95-3.97

Hardness: 3 to 3
Color: Pale blue, white, colorless, or slightly tinted yellow/red
Luster: Vitreous to pearly

Identified August 4, 2026More mineral →

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Physical properties

Formation & geological history

Typically forms in sedimentary environments, specifically in evaporite deposits associated with beds of gypsum, anhydrite, and halite, as well as in cavities in limestones and sandstones.

Uses & applications

Primary source of the element strontium, used in pyrotechnics (red fireworks), ceramic magnets, and metallurgy; also highly sought after by mineral collectors and for crystal healing/decorative purposes.

Geological facts

Celestine gets its name from the Latin word 'caelestis,' meaning heavenly, in allusion to the occasional delicate blue color of the mineral. Fine crystal geodes can be found in Madagascar.

Field identification & locations

Easily identified by its characteristic soft blue color, low Mohs hardness (easily scratched by a copper coin), perfect cleavage, and relatively high heft (specific gravity) for a non-metallic mineral. Common localities include Madagascar, the USA, Spain, and Mexico.