mineral

Small polished dark-blue stone, likely sodalite or blue aventurine

Probable sodalite (Na8(Al6Si6O24)Cl2); identification is uncertain from the image

AI-generated identification · may be incorrect

Dark blue, fine-grained, smoothly polished, with a dull-to-waxy luster and no visible crystal faces. Sodalite has Mohs hardness 5.5–6, imperfect cleavage, cubic structure, and specific gravity about 2.27–2.33; the pale crust may be matrix or residue.

Identified August 24, 2026More mineral →

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Physical properties

Formation & geological history

Sodalite forms in silica-poor, sodium-rich igneous rocks such as nepheline syenite, generally in alkaline intrusive environments. Common material is geologically young relative to Earth history, with age depending on its host rock.

Uses & applications

Used as a lapidary stone, cabochon, bead, carving material, and ornamental aggregate. Small polished pieces typically have modest value.

Geological facts

Its blue color commonly comes from sulfur-related defects and minor impurities; white calcite veining is frequent in sodalite specimens.

Field identification & locations

Look for royal-blue color, white calcite veining, relatively low hardness, and a nonmetallic appearance; lazurite, dumortierite, and dyed stones can look similar. Common sources include Canada, Brazil, Namibia, and Russia.