Sodalite

Sodalite is known for its beautiful blue color that rivals a nice lapis lazuli, but with a far more significant amount of calcite veining than is seen with lapis lazuli. Additionally, sodalite can also have pyrite inclusions like lapis lazuli which is why it is sometimes miss-identified by the untrained gemologist or jeweler. Here are the gemological properties to help you identify this excellent gemstone material that is both plentiful and affordable, and makes beautiful jewelry items:

Chemical: chloric sodium aluminum silicate (the sodium content is the basis for the name of this gemstone)
Refractive Index: 1.48
Mohs' Hardness: 5 - 6
Crystal System: Cubic (isometric) although rarely found in crystal form
Specific Gravity: 2.13 - 2.29
Opaque to slightly translucent in finer qualities
Identification: Easy separation from lapis lazuli and all other similar gemstones based on a strong orange reaction to long wave fluorescence as seen below.

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