mineral

Polished sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

AI-generated identification · may be incorrect

Usually deep royal-blue with white calcite veining; glassy to greasy luster, massive rather than visibly crystalline, Mohs hardness 5.5–6, and specific gravity about 2.2–2.4. The rounded, glossy surface indicates a tumbled or polished specimen.

Identified August 26, 2026More mineral →

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Physical properties

Formation & geological history

Forms in silica-poor, sodium-rich igneous environments, especially nepheline syenites and related alkaline rocks. Most gem-quality material comes from Canada, Brazil, Namibia, and Russia; specimens are generally geologically young to Precambrian depending on locality.

Uses & applications

Used as an ornamental stone, beads, cabochons, carvings, and polished specimens; rarely used as a minor industrial mineral.

Geological facts

Its blue color is caused by sulfur-related defects in the crystal structure, while white bands are commonly calcite. It is often confused with lapis lazuli, but sodalite typically lacks abundant metallic-gold pyrite flecks.

Field identification & locations

Identify it by its strong blue color, white veining, moderate hardness, and lack of pyrite; a streak test is white, though it may scratch more easily than quartz. Common localities include Bancroft, Ontario, Brazil, and Namibia.