Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Tangier (DOME31.JRG)
By Jeff R. Graham
Copyright 2007
85.6% Light Return
Angles for R.I. = 1.62
67 facets + 6 facets on girdle = 73
6-fold, mirror-image symmetry
96 index
L/W = 1.155 T/W = 0.226 T/L = 0.196 P/W = 0.419 C/W = 0.410
H/W = (P+C)/W+0.02 = 0.849 P/H = 0.494 C/H = 0.483
Vol./W^3 = 0.353
PAVILION
CROWN
Addition # 13 – Cut this in refractive indexes 1.62 to 2.14 with no changes. This is designed for light to mediumly saturated material and is not hard to cut. This cuts a very bright stone with a lot of sparkle.
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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