Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Sheila (MC113.JRG)
By Jeff R. Graham
Copyright 2002
79.2% Light Return
Angles for R.I. = 1.62
124 facets + 18 facets on girdle = 142
3-fold, mirror-image symmetry
96 index
L/W = 1.039 T/W = 0.459 T/L = 0.442 P/W = 0.506
C/W = 0.201 H/W = (P+C)/W+0.02 = 0.726 P/H = 0.696 C/H = 0.276 Vol./W^3 = 0.259
PAVILION
CROWN
Addition # 12 – Cut in refractive indexes 1.62 to 2.14 (83.3%) with no changes. This is really nice in medium colored material and needs to be cut in a large size. This cuts faster than it looks.
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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