Celestine
Image: Didier Descouens (CC BY-SA 4.0)
Mineral NameCelestine
Chemical FormulaSrSO4
Mohs Hardness3
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {001}, good on {210}, fair on {010}
Fractureconchoidal
Specific Gravity3.96
Colorspale blue, white, colorless
Transparencytransparent
Type LocalityFloristella Mine, Valguarnera, Enna Province, Sicily, Italy
Mineral GroupSulfates
Usessource of strontium, pyrotechnics, ceramics, collector
Associated Mineralsaragonite, sulfur
Rarityuncommon
Description
This specimen displays numerous pale blue to colorless, prismatic celestine crystals radiating from and growing upon a matrix of smaller, white to cream-colored aragonite crystals, with hints of yellow sulfur. The celestine crystals are well-formed and exhibit good transparency.
Geological Context
Celestine typically forms in sedimentary rocks, especially in evaporite deposits, limestones, and dolomites, often precipitating from hydrothermal solutions or through diagenetic replacement processes.
