Celestine
Celestine is a mineral consisting of sulphate strontium (SrSO4). Its name derives from the Latin word Caelestis, which was influenced by the well-known shades of sky blue of the crystals, meaning “celestial” This mineral can occur as crystals in geodes. Celestine may also appear in sedimentary rock as fibers, rivers, lakes, and beds of the ocean. Along with Gypsum, Anhydrite and Halite, the crystals are often also seen growing.
In small amounts, Celestine is present worldwide. In Madagascar and Sicily, Italy, the light blue specimens that the name is taken from are found. Colorless, white, light blue, pink, pale green, pale brown and black can occur as well.