mineral
Polished blue stone, likely sodalite or dyed quartz
Possibly sodalite (Na₈Al₆Si₆O₂₄Cl₂) or artificially dyed quartz/chalcedony; image alone is inconclusive
AI-generated identification · may be incorrectSmall rounded cabochon with vivid cobalt-blue color, vitreous-to-waxy luster, and polished surface. Sodalite has Mohs hardness 5.5–6 and poor cleavage; quartz has hardness 7 and no cleavage.
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Physical properties
Small rounded cabochon with vivid cobalt-blue color, vitreous-to-waxy luster, and polished surface. Sodalite has Mohs hardness 5.5–6 and poor cleavage; quartz has hardness 7 and no cleavage.
Formation & geological history
Natural sodalite forms in silica-poor alkaline igneous rocks; quartz/chalcedony forms from silica-rich fluids. The smooth shape indicates human tumbling or polishing, and the intense even blue may indicate dyeing.
Uses & applications
Used as an inexpensive cabochon, bead, carving, or jewelry stone; sodalite is also a decorative lapidary material. Typical small specimens have modest commercial value.
Geological facts
Sodalite commonly shows white calcite veining, whereas dyed quartz may reveal color concentrated in fractures or porous areas. A hardness, streak, magnification, or UV test would help distinguish them.
Field identification & locations
Common sources include Brazil, Canada, Namibia, and Afghanistan for sodalite; dyed quartz/chalcedony is widely processed worldwide. Estimated value: $2–$15 for a small polished piece, or up to $25–$50 if confirmed attractive natural sodalite.
