Celestine
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 4.0)
Mineral NameCelestine
Chemical FormulaSrSO₄
Mohs Hardness3
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {001}, good on {210}, imperfect on {010}
Fractureuneven
Specific Gravity3.96
Colorsyellowish-brown, orange
Transparencytransparent
Type LocalityFloristella Mine, Valguarnera, Enna Province, Sicily, Italy
Mineral GroupSulfates
Usessource of strontium, fireworks, ceramics, collector
Associated Mineralssulfur, calcite, gypsum
Rarityuncommon
Description
This specimen features yellowish-brown to orange celestine crystals, some with a vitreous luster, partially covered by a white, drusy mineral. Bright yellow sulfur is visible at the base and interspersed within the specimen.
Geological Context
Celestine commonly forms in sedimentary rocks, particularly in evaporite deposits, limestones, and dolomites, often found in vugs and geodes. The Sicilian deposits are famous for celestine associated with sulfur in gypsum-bearing sedimentary sequences.
