mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

Hardness: 5.5 - 6.0; Color: Royal blue to deep violet-blue with white streaks (calcite); Luster: Vitreous to greasy; Crystal structure: Cubic; Cleavage: Poor; Specific gravity: 2.27 - 2.33

Hardness: 5
Color: Royal blue to deep violet-blue with white streaks (calcite)
Luster: Vitreous to greasy

Identified March 18, 2026More mineral →

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Physical properties

Hardness: 5.5 - 6.0; Color: Royal blue to deep violet-blue with white streaks (calcite); Luster: Vitreous to greasy; Crystal structure: Cubic; Cleavage: Poor; Specific gravity: 2.27 - 2.33

Formation & geological history

Formed in sodium-rich igneous rocks such as nepheline syenites or phonolites through the crystallization of magma or via metasomatic processes in marbles. Often found in alkaline plutonic environments.

Uses & applications

Primarily used as an ornamental gemstone for jewelry (beads, cabochons), carvings, and decorative aggregate. It is also used occasionally as a minor industrial source of sodium or as a low-cost substitute for Lapis Lazuli.

Geological facts

Sodalite was first discovered in Greenland in 1811 but became extremely popular after 1891 when large deposits were found in Ontario, Canada. It is often called 'Princess Blue' in honor of Princess Margaret's visit to the Bancroft mines.

Field identification & locations

Identify in the field by its distinct deep blue color, white calcite veins, and lack of pyrite inclusions (which distinguishes it from Lapis Lazuli). It may fluoresce a bright orange-red under long-wave UV light. Common locations include Canada, Brazil, Russia, and Namibia.