Composed of strontium sulfate, Celestine/Celestite is named for its delicate blue color. Its name is derived from the latin caelestis, meaning celestial. Celestine occurs as crystals, compact massive, and fibrous forms. Often associated with gypsum, anhydrite, and halite. Pale blue specimens are found in Madagascar, while white and orange variates occur in Bristol, UK. Otherwise, the mineral can be found worldwide. It occurs as tabular and prismatic crystals.