Selenite is a crystalline variety of gypsum (hydrated calcium sulfate) that forms transparent to translucent crystals with a distinctive silky to vitreous luster, named after Selene, the Greek goddess of the moon, due to its ethereal, moon-like glow. This soft mineral typically appears as colorless to white fibrous crystals that can grow to enormous sizes, creating natural towers and wands that have become iconic in crystal collecting and metaphysical practices. Selenite's unique property of transmitting light along its crystalline fibers creates an internal luminosity that seems to glow from within, making it one of the most visually striking and recognizable minerals in both raw and polished forms.
