Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Crystal Keen Glitter (MC120.JRG)
By Jeff R. Graham
Copyright 2006
82.7% Light Return
Angles for R.I. = 1.62
103 facets + 15 facets on girdle = 118
3-fold, mirror-image symmetry
96 index
L/W = 1.030 T/W = 0.360 T/L = 0.350 P/W = 0.478
C/W = 0.204 H/W = (P+C)/W+0.02 = 0.702 P/H = 0.681 C/H = 0.291 Vol./W^3 = 0.260
Addition # 12 – Cut in refractive indexes 1.62 to 2.14 with no changes. This is designed for Tourmaline and works especially well in light to medium saturations. It is not too hard to cut and I like it in pink Tourmaline.
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
This edited version of an article by the late Jeff Graham is part of a special archived informational series from Gram Faceting. Used with permission.
