Sodalite

Physical Properties

Hardness: 5.5-6 on Mohs scale. Color: Royal blue to dark blue, often with white calcite inclusions. Luster: Vitreous to greasy. Crystal structure: Cubic (Isometric). Specific gravity: 2.27-2.33.

Formation & Geological History

Formed in igneous rocks that crystallized from sodium-rich magmas (nepheline syenites and phonolites). Often found in hydrothermal veins and rarely in contact metamorphic rocks.

Uses & Applications

Used primarily as a gemstone in jewelry (cabochons and beads), decorative carvings, and as an ornamental architectural stone (slabs and tiles).

Geological Facts

Sodalite is a member of the sodalite group and is named after its sodium content. It was discovered in Greenland in 1811 but became popular in 1891 after vast deposits were found in Ontario, Canada, earning it the nickname 'Princess Blue'.

Field Identification & Locations

Identify by its distinctive blue color and white veins of calcite. Unlike Lapis Lazuli, it rarely contains golden pyrite specks and is slightly more translucent when thin. Common locations include Canada, Brazil, Russia, and Namibia.

Identified on: 4/23/2026

Mode: Standard