Sodalite Rock Professor Image

Sodalite is named for its sodium content. It is a dark blue semiprecious mineral of the feldspathoid group. It has a hardness of 5.5-6 and a specific gravity of about 2.3, making it lighter than quartz.

Brazilian sodalite commonly occurs with veinlets of calcite. Fairly rare, sodalite is also found in Canada and Russia. Sodalite is one of the common constituents of lapis lazuli.

Chemistry: Chloric sodium aluminum silicate ♦ Group: Feldspathoid ♦ Color: White, blue, gray ♦ Luster: Vitreous or greasy ♦ Crystal system: Isometric ♦ Transparency: Opaque, crystals are transparent ♦ Moh's hardness: 6 - 6.5 ♦ Localities: Brazil, Greenland, India, Canada, Namibia, Russia and Montana