Sodalite

Physical Properties

Hardness: 5.5-6 on Mohs scale. Color: Royal blue to violet-blue, often with white calcite veining. Luster: Vitreous to greasy. Crystal structure: Cubic. Cleavage: Poor. Specific Gravity: 2.27-2.33.

Formation & Geological History

Formed in silica-poor igneous rocks such as nepheline syenites and phonolites. It can also occur in contact metamorphic rocks where limestone has been altered. Major deposits are found in Canada, Greenland, Namibia, and Brazil.

Uses & Applications

Commonly used as a gemstone for beads, cabochons, and decorative carvings. It is also used in industry as a constituent of some ceramics and pigments, or as a decorative architectural stone.

Geological Facts

Sodalite was first discovered in Greenland in 1811 but became popular after large deposits were found in Ontario, Canada in 1891. It is often confused with Lapis Lazuli, though Sodalite lacks the golden pyrite inclusions common in Lapis.

Field Identification & Locations

Identify by its deep blue color and characteristic white calcite streaks. Unlike Lapis, it rarely contains pyrite and has a lower specific gravity. It often fluoresces bright orange under long-wave UV light.

Identified on: 5/9/2026

Mode: Standard