mineral

Celestine (or Celestite) on Matrix

Celestine (SrSO4)

Hardness: 3 to 3.5 on Mohs scale. Color: Pale blue, white, or colorless. Luster: Vitreous to pearly. Crystal structure: Orthorhombic. Cleavage: Perfect in one direction. Specific Gravity: 3.9 to 4.0.

Hardness: 3 to 3
Color: Pale blue, white, or colorless
Luster: Vitreous to pearly

Identified April 19, 2026More mineral →

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Physical properties

Hardness: 3 to 3.5 on Mohs scale. Color: Pale blue, white, or colorless. Luster: Vitreous to pearly. Crystal structure: Orthorhombic. Cleavage: Perfect in one direction. Specific Gravity: 3.9 to 4.0.

Formation & geological history

Formed in sedimentary rocks, particularly evaporite deposits involving strontium-rich fluids. Often found in geodes within limestone or dolostone. Formed during the Phanerozoic eon.

Uses & applications

Primary source of the element strontium, used in fireworks (red flames), glass manufacturing, and as a collector's mineral specimen.

Geological facts

The name is derived from the Latin 'caelestis', meaning celestial or heavenly, in reference to its characteristic sky-blue color. The largest geode in the world, located in Ohio, is a Celestine geode.

Field identification & locations

Identify by its sky-blue tint, high density (heavy for its size), and lack of effervescence in acid. Commonly found in Madagascar, Sicily, and Ohio, USA. Avoid washing with water for long periods as it can be slightly soluble.

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