mineral

Polished blue stone, likely sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂; possibly dyed howlite or blue calcite

AI-generated identification · may be incorrect

Deep royal-blue and white-gray mottling with a polished vitreous-to-waxy luster; likely hardness 5.5–6 (sodalite), massive rather than visibly crystalline, with indistinct cleavage. Exact identification is limited by the photograph; strong color saturation may indicate dyeing.

Identified September 19, 2026More mineral →

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Physical properties

Formation & geological history

Sodalite forms in silica-poor, sodium-rich igneous rocks, especially nepheline syenites, typically during Precambrian to younger magmatic events. Major sources include Canada, Brazil, Namibia, and Russia.

Uses & applications

Used as ornamental stone, beads, cabochons, carvings, and polished spheres; not generally used structurally. Common tumbled specimens usually have modest commercial value.

Geological facts

Natural sodalite commonly has white calcite veining and a blue streak; it is generally nonfluorescent or weakly orange under ultraviolet light. A glassy appearance, unusually uniform blue, or color concentrated in fractures suggests dye treatment.

Field identification & locations

Field tests include hardness against a steel knife, streak on unglazed porcelain, and checking for dye in cracks or acetone-transfer color; avoid damaging a finished piece. Typical value is $10–$40 for a polished sphere of this size, or $30–$100 if exceptionally natural and high quality.