Sodalite with Natrolite
Sodalite var. Hackmanite or complex feldspathoid-rich rock containing Sodalite · Semi-Precious Gemstone, Decorative Stone, and Mineral Specimen
Crystal System
Cubic (Sodalite), Tumbled and polished irregular shape
Mineral Group
Silicates, specifically Tectosilicates (Feldspathoid group)
Chemical Formula
Na8Al6Si6O24(Cl)2 (Sodalite) with associated Na2Al2Si3O10·2H2O (Natrolite) or Albite
Formation Process
Igneous and metasomatic processes, crystallizing from sodium- and aluminum-rich magmas deficient in silica, often associated with nepheline syenites and pegmatites.
About This Crystal
A polished tumbled stone exhibiting a deep indigo-blue to royal blue base color, prominently veined with white and reddish-orange or peach-colored patches. The surface is smooth and lustrous, displaying a vitreous to greasy luster with opaque to sub-translucent light penetration.
Physical Characteristics
Color ranges from deep blue to white and orange-pink (due to natrolite or feldspar inclusions). Streak is white. Cleavage is poor in distinct directions. Fracture is uneven to conchoidal. Specific gravity is approximately 2.15 to 2.35. Tenacity is brittle.
Optical Properties
Isotropic (singly refractive) for the sodalite component, with a refractive index around 1.483 to 1.487. Pleochroism is typically weak or absent in mass varieties.
Hardness & Durability
Origin Region
Notable sources include Ontario (Canada), Greenland, Brazil, India, and Russia. Typically forms in silica-poor igneous rocks such as nepheline syenites.
Hardness & Durability
Mohs hardness of 5.5 to 6. Moderate durability. Prone to scratching by quartz and harder minerals. Fairly sensitive to sharp impacts due to brittle tenacity.
Care & Maintenance
Clean with warm, soapy water and a soft cloth. Avoid harsh chemical cleaners, ultrasonic cleaners, and steam cleaning. Store separately from harder gemstones to prevent scratching.
Rarity & Value
Common to uncommon. Value is modest, primarily determined by intensity of blue color, attractive contrasting white veining, and stone size. Commonly used for carvings, cabochons, and tumbled stones without synthetic enhancements.
Special Characteristics
Some varieties of sodalite (such as hackmanite) exhibit tenebrescence (color change when exposed to sunlight), and the white veining may fluoresce a patchy orange or yellow under UV light.
Lore & History
Historically used as an ornamental stone and occasionally for ancient carvings. In modern metaphysical practices, sodalite is traditionally associated with the third-eye and throat chakras, believed to enhance logic, rational thought, truth, and emotional balance. These are traditional beliefs and not scientifically validated properties.