Physical Features
1. Color- Gray, white, blue, green, yellow violet.
2. Streak- Colorless, white, light blue.
3. Luster- Vitreous to greasdy.
4. Cleavage- Poor to distinct.
5. Transparency- Transparent to translucent.
6. Fracture-Uneven to conchoidal.
7. Hardness- 5.5-6.
8. Forms- Granular to Massive.
9. Crystal feature- Cubic.
Sodalite is a rich blue mineral named for it's high sodium aluminum silicate chloride. In mineralogy it maybe classed as a feldspathoid. Sodalite typically occures in massive granular forms, which crystals are relatively rare and are dodecahedral or octahedral. Much of Sodalite is found in veins of dry silica-poor plutonic igneous rocks such as nepheline syenites, pegmatites and phonolites. On the rare occassion may be found in volcanic ejecta and metamorphosed limestones and dolomite. Hackmanite is a rare but highly important variety of Sodalite which has been said to exhibit the ability to change color when exposed to sunlight. These occurrences happen through out the world.
