Strontium sulfate, the principal ore of strontium. Often forms beautiful pale blue crystals in geodes. Color: Pale blue, white, colorless, reddish. Luster: Vitreous to pearly. Streak: White. Cleavage: Perfect in two directions. Hardness: 3-3.5. Transparency: Transparent to translucent. Crystal system: Orthorhombic. Chemical formula: SrSO₄. Specific gravity: 3.95-3.97. Formation: Precipitates from strontium-bearing brines in sedimentary environments, often in evaporites and limestones. Common geological settings: Madagascar giant geodes , USA, Mexico, Italy; found in limestones and evaporite sequences. Common look-alikes and related entries: Barite, Calcite, Angelite.
Blue minerals — Place this specimen in a broader field-identification workflow.
Sources, scope & corrections
These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.
Editorial owner
GeoMiner
Last updated
2026-03-30T14:37:04.070219+00:00
Review status
Published; not independently peer-reviewed
IMA–CNMNC List of Mineral Names — International Mineralogical Association. Official mineral-name, nomenclature, and classification records.
Mineral ID Key — Mineralogical Society of America. Physical-property identification methods, repeat-testing guidance, and limitations.
Strontium sulfate, the principal ore of strontium. Often forms beautiful pale blue crystals in geodes.
How can you identify Celestine?
Compare several properties rather than relying on colour alone. This entry records colour: Pale blue, white, colorless, reddish; lustre: Vitreous to pearly; streak: White; Mohs hardness: 3-3.5; cleavage: Perfect in two directions; crystal system: Orthorhombic; transparency: Transparent to translucent. Confirm an important identification with additional field tests or qualified laboratory work.
How does Celestine form?
Precipitates from strontium-bearing brines in sedimentary environments, often in evaporites and limestones.
Where is Celestine commonly found?
Madagascar giant geodes , USA, Mexico, Italy; found in limestones and evaporite sequences.
What is Celestine commonly confused with?
Celestine may be confused with Barite, Calcite, Angelite. Compare multiple diagnostic properties because colour and surface appearance can overlap.
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