mineral
Polished blue stone, likely sodalite or dyed agate
Most consistent with sodalite (Na₈(Al₆Si₆O₂₄)Cl₂), though the image cannot confirm composition
AI-generated identification · may be incorrectDark blue, opaque, glassy-to-waxy polished luster with faint mottling; sodalite has Mohs hardness 5.5–6, imperfect cleavage, cubic structure, and specific gravity about 2.25–2.35. The rounded shape is tumbled or cabochon-polished.
Identified More mineral →
Explore Polished blue stone, likely sodalite or dyed agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark blue, opaque, glassy-to-waxy polished luster with faint mottling; sodalite has Mohs hardness 5.5–6, imperfect cleavage, cubic structure, and specific gravity about 2.25–2.35. The rounded shape is tumbled or cabochon-polished.
Formation & geological history
Natural sodalite forms in silica-poor, alkaline igneous rocks such as nepheline syenite, generally during Precambrian to younger magmatic events. Similar blue specimens may instead be dyed chalcedony or glass.
Uses & applications
Used for carvings, cabochons, beads, ornaments, and decorative stone; lower-grade material is inexpensive and primarily collectible.
Geological facts
Sodalite’s intense royal-blue color commonly contains white calcite veining, which is not clearly visible here. Strongly uniform blue color can indicate dyeing or synthetic material.
Field identification & locations
Check for natural white calcite veins, granular texture, and hardness: sodalite should resist scratching by a steel knife but be scratched by quartz. Common sources include Canada, Brazil, Namibia, and Russia.
