The well formed crystals in this piece reflect light beautifully. It's important to note in direct sunlight the blue colour may fade to colourless. For this reason celestine should not be placed close to a sunny window.
Celestine and celestite come from the Latin '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.