mineral

Blue Celestite (with Galena)

Strontium sulfate (SrSO4) and Lead sulfide (PbS)

Hardness: 3-3.5 (Celestite) / 2.5 (Galena); Color: Sky blue to colorless with silvery-grey metallic patches; Luster: Vitreous/Pearly (Celestite) and Metallic (Galena); Crystal Structure: Orthorhombic (Celestite) and Cubic (Galena); Cleavage: Perfect; Specific Gravity: 3.9-4.0.

Hardness: 3-3
Color: Sky blue to colorless with silvery-grey metallic patches
Luster: Vitreous/Pearly (Celestite) and Metallic (Galena)

Identified May 17, 2026More mineral →

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Physical properties

Formation & geological history

Formed in sedimentary rocks, typically within cavities or geodes. Often found in evaporite deposits or as a secondary mineral in hydrothermal veins. Some specimens are millions of years old, primarily from the Cretaceous period in certain famous deposits.

Uses & applications

Celestite is the primary source of Strontium, used in fireworks (red flames), flares, and glass production. Galena is the primary ore of lead. High-quality specimens are popular for crystal healing, meditation, and mineral collections.

Geological facts

The world's largest gemstone geode is a celestite geode located in Ohio, USA, measuring 35 feet deep. The name Celestite is derived from the Latin 'caelestis', meaning celestial or heavenly, referring to its sky-blue color.

Field identification & locations

Identify in the field by its distinct pale blue color, high weight compared to size (high specific gravity), and fragile, prismatic crystal forms. Commonly found in Madagascar, Ohio (USA), and Poland.

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