mineral

Celestite

Celestine (SrSO4)

Hardness: 3-3.5 on the Mohs scale. Color: Pale blue, white, colorless, sometimes yellowish or reddish. Luster: Vitreous to pearly. Crystal structure: Orthorhombic. Cleavage: Perfect in one direction, good in another. Specific gravity: 3.9-4.0.

Hardness: 3-3
Color: Pale blue, white, colorless, sometimes yellowish or reddish
Luster: Vitreous to pearly

Identified August 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed in sedimentary environments, often in cavities of limestone, sandstone, and evaporite deposits, precipitated from marine waters.

Uses & applications

Used primarily as the principal ore of the element strontium, utilized in fireworks, flares, and ceramics, as well as highly sought after by mineral collectors.

Geological facts

Named from the Latin word 'caelestis' meaning celestial, referring to the delicate sky-blue color of many specimens. Madagascar produces some of the finest crystal clusters in the world.

Field identification & locations

Easily identified by its characteristic soft blue color, high density (heavy for its size), and distinct orthorhombic cleavage. Found famously in Madagascar, Italy, Spain, and the USA (Ohio).