paraiba tourmaline

Product details

Absorption Spectrum. Usually not diagnostic for tourmalines. ...
Birefringence. 0.013-0.024.
Birthstone. October.
Cleavage. None.
Colors. Neon blue, greenish blue, blue-green, green, mint green, and, very rarely, violet, purple, and pink.
Crystallography. Hexagonal (trigonal)
Dispersion. ...
Enhancements.