The mineral sodalite is a chlorine-containing sodium aluminum silicate with the chemical formula Na8Al6Si6O24Cl2. The tectosilicate belongs to the feldspar substitutes. The white, gray, pink, green or azure sodalite has a glassy to greasy luster, a white streak color and the cleavage is poor along the crystal plane [110]. The average density is 2.29 and the hardness is 6. The crystal system is cubic and the mineral is not radioactive. The name of the mineral sodalite is derived from its chemical composition; the English sodium means "sodium". Sodalite occurs mainly in nepheline syenites, phonolites and other felsic silica-poor igneous and metamorphic rocks. The type locality is located in the Ilimaussaq massif in Greenland.