mineral

Celestite

Strontium Sulfate (SrSO4)

Hardness: 3 - 3.5 on Mohs scale; Color: Pale blue, light blue-grey, white, colorless; Luster: Vitreous (glassy) to pearly on cleavage planes; Crystal structure: Orthorhombic; Cleavage: Perfect in one direction, good in two others; Specific gravity: 3.9 - 4.0

Hardness: 3 - 3
Color: Pale blue, light blue-grey, white, colorless
Luster: Vitreous (glassy) to pearly on cleavage planes

Identified July 24, 2026More mineral →

Explore Celestite in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed primarily in sedimentary rocks such as limestones and dolostones through the evaporation of ocean waters containing dissolved strontium, or as primary vein deposits in hydrothermal settings.

Uses & applications

Major ore of strontium used in fireworks, flare production, and glass manufacturing for color television cathode-ray tubes. Widely popular among mineral collectors and in metaphysical crystals market.

Geological facts

Celestite gets its name from the Latin word 'coelestis', meaning 'heavenly', referring to its delicate sky-blue color. The finest quality geode specimens typically originate from Madagascar.

Field identification & locations

Identified by its pale blue color, high specific gravity (feels surprisingly heavy for its size), distinct cleavage, and low hardness (scratched easily by a knife or copper coin). Found in Madagascar, USA, Mexico, and Spain.