Sodalite

Physical Properties

Hardness: 5.5-6.0 Mohs; Color: Royal blue to grey with white calcite streaks; Luster: Vitreous to greasy; Crystal Structure: Isometric; Density: 2.27-2.33 g/cm3; Cleavage: Poor/indistinct.

Formation & Geological History

Formed primarily in alkaline igneous rocks like nepheline syenites and phonolites through magmatic crystallization. It is a member of the feldspathoid group.

Uses & Applications

Used predominantly as a gemstone for jewelry, decorative carvings, beads, and sometimes as an architectural surface material (countertops/slabs).

Geological Facts

Sodalite is often confused with Lapis Lazuli, but it lacks the gold-colored pyrite specks characteristic of Lapis. It was discovered in Greenland in 1811 but became popular after large deposits were found in Ontario during a royal visit in 1901.

Field Identification & Locations

Identify by its deep blue color and characteristic white calcite veins. Unlike Lapis, it is rarely found with pyrite. It occurs in silica-poor igneous environments. Notable locations include Canada, Brazil, Namibia, and Russia.

Identified on: 5/19/2026

Mode: Standard