Angelite is the trade name for anhydrite, a calcium sulfate mineral (CaSO₄) that forms through dehydration and is characterized by its pale blue to grayish color. It usually occurs in massive and granular form, though rarely in crystals, and is soft, with a hardness of 3.5 to 4 on the Mohs scale. Its name derives from its celestial appearance and its purported calming and spiritual properties.