Paraiba Tourmaline Classification
Bright Electric Blue To Green, Violet To Purplish
appearance, refractive index and high birefringence; then optic figure, pleochroism and specific gravity. Has intense saturated color.
Crystal habit is prismatic and may be 3, 6 or 9-sided; often a triangular prism with convex faces, and often long and heavily striated parallel to the c axis. Pyramidal terminations are common. Tourmaline is part of an isomorphous series.Cuprian Elbaite must have copper present to be called Paraiba tourmaline.Originally found in the Brazilian State of ParaibaDark material might have a birefringence as high as 0.040.