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Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Double Dutch Deep (DOME22.JRG)
By Jeff R. Graham
Copyright 2007
79.1% Light Return
Angles for R.I. = 1.62
109 facets + 12 facets on girdle = 121
12-fold symmetry
96 index L/W = 1.000 T/W = 0.341 T/L = 0.341 P/W = 0.419
C/W = 0.325 H/W = (P+C)/W+0.02 = 0.764 P/H = 0.549 C/H = 0.425 Vol./W^3 = 0.309Addition # 13 - Cut in refractive indexes 1.62 to 2.14 with no changes. Cut this in lightly saturated materials. It works great in light to pale Afghan Tourmaline which is what I designed it for.

Random - Cosine - ISO
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