Celestine
Image: Ivar Leidus (CC BY-SA 4.0)
Mineral NameCelestine
Chemical FormulaSrSO4
Mohs Hardness3.5
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {001}, good on {210}, distinct on {010}
Fractureuneven to conchoidal
Specific Gravity3.97
Colorspale blue, colorless, white
Transparencytransparent
Type LocalitySakoany deposit, Katsepy, Mitsinjo, Boeny, Madagascar
Mineral GroupSulfates
Usessource of strontium, collector's specimens
Associated Mineralsgypsum, anhydrite, sulfur, calcite, dolomite
Raritycommon
Description
This image displays a cluster of well-formed, pale blue celestine crystals, exhibiting excellent transparency and a vitreous luster. The crystals show distinct blocky to tabular habits, characteristic of the mineral.
Geological Context
Celestine typically forms in sedimentary rocks, particularly in limestones and sandstones, often associated with evaporite deposits. It can also occur in hydrothermal veins and as a gangue mineral.
