Sodalite

Physical Properties

Hardness: 5.5-6.0 Mohs; Color: Royal blue with white streaks or veins; Luster: Vitreous to greasy; Crystal Structure: Isometric (cubic); Cleavage: Poor; Specific Gravity: 2.27-2.33.

Formation & Geological History

Formed in silica-poor igneous rocks such as nepheline syenites and phonolites. It orignates from sodium-rich magmas that crystallize in environments lacking quartz.

Uses & Applications

Primarily used as an ornamental gemstone, in carvings, jewelry, and as a decorative stone in architecture (countertops and tiles).

Geological Facts

Sodalite is often mistaken for Lapis Lazuli, but unlike Lapis, it rarely contains golden pyrite inclusions. It is also known as the 'Poet's Stone' and was famously used in the decoration of Marlborough House in London.

Field Identification & Locations

Identified by its rich blue color with white calcite veining. Commonly found in Bancroft (Ontario, Canada), Namibia, Brazil, and Greenland. It often fluoresces bright orange under long-wave UV light.

Identified on: 5/13/2026

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