Celestine also known as celestite is relatively soft so must be handled carefully. Although best known for its blue crystals they also occur in several other colours including white and can even be colourless. The mineral celestine also occurs in massive form meaning crystals grow as one large mass with no external visible shape.
The well formed crystals in this celestine mineral reflect light beautifully but it's important to note that in direct sunlight the blue colour may fade to colourless. For this reason celestine should not be placed close to a sunny window.
The names celestine and celestite come from the Latin word 'caelestis' meaning 'of (or) in the heavens' which metaphorically can also mean 'divine' or 'god-like'. Both names stem from the mineral's heavenly blue colour.
Interestingly celestine is the main source of the chemical element strontium which is widely used in fireworks and alloys. Strontium is a soft silvery white yellowish metal.