mineral

Sodalite

Sodalite, Na8(Al6Si6O24)Cl2

Hardness: 5.5 to 6 on Mohs scale; Color: typically rich royal blue with white calcite veining; Luster: vitreous to greasy; Crystal Structure: Isometric (cubic); Cleavage: poor; Specific Gravity: 2.27 to 2.33.

Hardness: 5
Color: typically rich royal blue with white calcite veining
Luster: vitreous to greasy

Identified April 6, 2026More mineral →

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Physical properties

Formation & geological history

Formed in silica-poor igneous rocks such as nepheline syenites and phonolites. It occurs when sodium-rich magma crystallizes in environments lacking sufficient silica to form feldspars. It is a member of the feldspathoid group.

Uses & applications

Used primarily as an ornamental gemstone for beads, cabochons, and carvings. In industry, it is sometimes used as a pigment or for its photochromic properties (tenebrescence) in specific varieties like hackmanite.

Geological facts

Sodalite is often confused with Lapis Lazuli; however, Sodalite lacks the golden pyrite specks characteristic of Lapis and has a lower specific gravity. It was famously discovered in Greenland in 1811 and became popular after large deposits were found in Ontario, Canada during a royal visit.

Field identification & locations

Identify in the field by its distinct azure-blue color, white streaks of calcite, and lack of pyrite. It will often fluoresce a bright orange or pink under long-wave UV light. Common locations include Canada (Bancroft), Brazil, Namibia, and Russia.