Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Lens (DOME4.JRG)
By Jeff R. Graham
Copyright 2007
80.6% Light Return
Angles for R.I. = 1.62
133 facets + 12 facets on girdle = 145
12-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.294 T/L = 0.294 P/W = 0.419
C/W = 0.295 H/W = (P+C)/W+0.02 = 0.734 P/H = 0.571 C/H = 0.402 Vol./W^3 = 0.277
PAVILION
CROWN
Addition # 13 – Cut this in refractive indexes 1.62 to 2.14 with no changes. This is an interesting cut and works well in any light to medium saturated material. This is not hard to cut.
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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