mineral

Celestite (Celestine) Geode

Strontium Sulfate (SrSO4)

Hardness: 3.0-3.5 (Mohs); Color: Pale blue to sky blue; Luster: Vitreous/Pearly; Crystal structure: Orthorhombic; Specific gravity: 3.9-4.0; Cleavage: Perfect in one direction.

Hardness: 3
Color: Pale blue to sky blue
Luster: Vitreous/Pearly

Identified April 5, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3.0-3.5 (Mohs); Color: Pale blue to sky blue; Luster: Vitreous/Pearly; Crystal structure: Orthorhombic; Specific gravity: 3.9-4.0; Cleavage: Perfect in one direction.

Formation & geological history

Formed as a sedimentary mineral within geode cavities in limestone or sandstone. These specimens are often found in Madagascar and are generally of Cretaceous geological age.

Uses & applications

Primary source of strontium for fireworks and tracer bullets; widely used in metaphysical practices, crystal collecting, and interior decor.

Geological facts

Celestite gets its name from the Latin 'caelestis', meaning 'heavenly' or 'celestial', referring to its sky-blue color. It can transition to a yellowish or colorless state if exposed to direct sunlight for extended periods.

Field identification & locations

Identify by its pale blue blocky or tabular crystals and high density (it feels heavy for its size). Commonly found in sedimentary deposits, notably in the Sakoany mine in Madagascar.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral