Sodalite is the third major mineral of the Feldspathoid group. It is comparatively rare than Nepheline and Leucite. It is found in blue and blue-voilet colors. Its chemical composition is Na4Al3Si3O12Cl. It is included in semi-precious gemstones. Its blue color helps to diagnose it. Its physical properties are as under:
- Physical Properties:
- It is found in cubic crystal systems.
- It has a poor cleavage and has an even fracture.
- It has a massive habit.
- It has a vitreous luster.
- It is mostly found in blue color, but in rare cases it is also found in white, grey and green colors.
- Its specific gravity ranges from 2.15 to 3.0.
- Uses of Sodalite:
- A semiprecious gemstone often used to produce cabochons, beads, and tumbled stones. An ornamental stone often used to make small sculptures. “Sodalite granite” is a rare nepheline syenite with minor to abundant sodalite that is cut as a dimension stone for interior use. A less costly alternative to lapis lazuli.
- Sodalite is a general of the feldspathoid group, that is why it naturally occurs in igneous rock; ”sodalite granite” and along with ”Nepheline” in Nepheline syenite. Both are found in igneous rocks of recent lavas.