The word quartz is thought to come from the German word "quarz", but the origin of that word is not known. The word crystal, however, comes from the Greek word "krystallos" which means ice. There are many traditional uses of quartz. Ancient Japanese believed quartz formed from the breath of a white dragon, and regarded it as representing perfection. Australian Aborigines used quartz in rain rituals. Crystals skulls were reportedly made by Atlanteans and are believed by some to be living entities. Clear quartz formed into spheres have been used as crystal balls to predict the future at least since the middle ages.