Answer: sodalite

AnswerCrossword Clue
SODALITEBlue mineral
SODALITETranslucent mineral resembling marble.
sodalitea transparent to translucent mineral that consists of a silicate of sodium and aluminum with some chlorine, has a vitreous or greasy luster, and is found in various igneous rocks
sodalitemineral, sodium aluminum silicate, Na4Al3Si3O12Cl, occurring massive and in crystals, usually blue in color and found in certain alkali-rich igneous rocks