mineral
Sodalite
Na8(Al6Si6O24)Cl2 (Tectosilicate / Tectofeldspathoid)
Hardness: 5.5 to 6 on Mohs scale. Color: Royal blue to deep denim blue with characteristic white veins or patches of calcite or feldspar. Luster: Vitreous to greasy. Crystal System: Cubic/Isometric. Cleavage: Poor in six directions. Specific Gravity: 2.14 to 2.40.
- Hardness
- 5
- Luster
- Vitreous to greasy
Identified More mineral →
Explore Sodalite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5.5 to 6 on Mohs scale. Color: Royal blue to deep denim blue with characteristic white veins or patches of calcite or feldspar. Luster: Vitreous to greasy. Crystal System: Cubic/Isometric. Cleavage: Poor in six directions. Specific Gravity: 2.14 to 2.40.
Formation & geological history
Sodalite forms primarily in silica-poor igneous rocks such as nepheline syenites, phonolites, and associated pegmatites. It crystallizes during late-stage magmatic processes where sodium and chlorine concentrations are high and silica content is low.
Uses & applications
Popular as an ornamental stone, for tumbled rocks, cabochons, beads, gemstone carvings, and decorative tiles. Highly valued in lapidary arts and crystal collecting.
Geological facts
Sodalite was first discovered in Greenland in 1811, but became famous as an ornamental stone after vast deposits were discovered in Bancroft, Ontario, Canada during a royal visit in 1891 (often called 'Princess Blue'). It fluoresces bright orange to yellow under shortwave ultraviolet light.
Field identification & locations
Identified by its distinctive royal blue color intermingled with white veins, lack of brassy pyrite flecks (which distinguishes it from lapis lazuli), and medium hardness. Found in Brazil, Canada (Bancroft), Greenland, Russia, Namibia, and the USA.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Limonite / Goethite (Iron Ore Mineral nodule)
FeO(OH)·nH2O / FeO(OH)
mineral
Schist
Schist
Metamorphic
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary