Precious opals are translucent to transparent and are illustrated by a combination of milky to pearly opalescence and an attractive play of many colors. These colors flash and change as a stone is viewed from different directions. There is a wide range in variety. Black opal, with a very dark gray or blue to black body color, is particularly rare and highly prized. White opal has light body colors. Fire opal is defined by yellow, orange, or red body color. White and Fire opals are more common.