White Moonstone Simulant

Heat treatment causes some of the alumina to crystallize out as corundum, which causes a diffuse reflection effect in the form of a moonstone-like sheen. The imitation moonstone synthetic spinel features a mirror-like coating on the back of the cabochon. The schiller-like effect is caused by exsolution of excess alumina which produces multitudes of tiny needles and can even produce star phenomena. The material is rare.