Sodalite

Physical Properties

Hardness: 5.5-6 (Mohs scale); Color: Royal blue to grey-blue with white/grey streaks; Luster: Vitreous to greasy; Crystal structure: Cubic (usually massive); Cleavage: Poor; Specific Gravity: 2.27-2.33

Formation & Geological History

Formed in sodium-rich igneous rocks (nepheline syenites and phonolites) or in contact-metamorphosed limestones. It is a feldspathoid mineral crystallizing from silica-poor magmas.

Uses & Applications

Primarily used as a decorative gemstone, in jewelry (beads, cabochons), carvings, and ornamental architectural tiles. It is also a popular collector's mineral.

Geological Facts

Sodalite is often confused with Lapis Lazuli, but Sodalite rarely contains the gold-colored pyrite specks common in Lapis. It was first discovered in Greenland in 1811 but became popular in 1891 when large deposits were found in Ontario, Canada.

Field Identification & Locations

Identify by its rich blue color with white calcite veining and lack of pyrite. In the field, look for it in alkaline igneous complexes. A key indicator is its orange/yellow fluorescence under long-wave ultraviolet light.

Identified on: 4/16/2026

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