Moonstone achieves a mystic and magical effect called adularescence when the stones’ layers reflect and scatter light. The color is usually white but occasionally blue with an appearance like rolling fog or smoke. For this unusual and spectacular light effect, this adularescent jewel is one of a class of gemstones called phenomenal gemstones, deemed so for displaying some special light interaction or “phenomena”. These dazzling light effects, occurring as a result of internal crystal structures, have captivated onlookers through the ages.