mineral

Celestine (or Celestite) Geode

Strontium Sulfate (SrSO4)

Hardness: 3 to 3.5 on Mohs scale; Color: Pale blue, white, or colorless; Luster: Vitreous to pearly; Crystal Structure: Orthorhombic; Cleavage: Perfect; Specific Gravity: 3.95 to 3.97

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

Identified May 22, 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; Specific Gravity: 3.95 to 3.97

Formation & geological history

Forms in sedimentary rocks as a primary precipitate from evaporated seawater, or in cavities within limestones and dolomites. Often found as geodes or nodules in stratigraphic layers ranging from the Paleozoic to the Cenozoic.

Uses & applications

Used as the primary source of Strontium for pyrotechnics (red flames), television glass production, and magnets. It is also a popular collector specimen and used in metaphysical practices.

Geological facts

The largest celestine geode in the world is located in Put-in-Bay, Ohio, and is 35 feet (11 meters) in diameter at its widest point. It was discovered in 1897 while digging a well.

Field identification & locations

Identify by its distinct pale blue color, high density (heavy for its size), and poor resistance to heat. Most commercial specimens are found in Madagascar, Ohio (USA), and Poland.

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