Angelite is a trade name for the blue variety of anhydrate. Although it occurs in several colours, only the blue variety is known as angelite. The vast majority of the crystals sold in the UK and USA come from Peru.
Anhydrate is a form of calcium sulphate. It occurs naturally in both an anhydrous (without water) and hydrated (with water) form. The hydrated variety is known as gypsum which is the main ingredient of plaster. When mixed with water gypsum hardens because of the process of crystallisation.
Anhydrate comes from the Greek 'anhydrous' meaning 'without water'.
Angelite is used for decorative purposes and can often be found as figurines particularly angels. This is because in the metaphysical world angelite is associated with heaven and the angelic realm.
Angelite is a soft and fragile crystal that must not be allowed to get wet or even be exposed to moisture. Water turns it white and over time it will degenerate into gypsum.