Feldspathoid

Sodalite

Royal to medium blue, often with white calcite or feldspathoid patches

Blue Royal Blue

Optical characteristics

Ref. index
1.483 – 1.487
Luster
Vitreous to greasy
Pleochroism
None None; cubic system is isotropic.
Fluorescence
Typically strong orange fluorescence under LW UV — a key identifier.

Source localities

Enhancement & treatment

Inclusions & features

Instruments used