Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)

Optimal Hex (B23.JRG)
By Jeff R. Graham
Copyright 2001
90.5% Light Return
Angles for R.I. = 1.62
61 facets + 6 facets on girdle = 67
3-fold, mirror-image symmetry
96 index
L/W = 1.073 T/W = 0.488 T/L = 0.455
P/W = 0.472 C/W = 0.153
H/W = (P+C)/W+0.02 = 0.645
P/H = 0.732 C/H = 0.237
Vol./W^3 = 0.246

Addition # 5 - This is fast and fairly easy to cut and works well in almost any material. This is designed for the “c” axis crystal shape that is fairly common in Tourmaline. It will work in R.I. 1.62 to 1.76 (88.9%) with no changes.

 

 

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