Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Asterism (MC108.JRG)
By Jeff R. Graham
Copyright 2006
78.6% Light Return Angles for
R.I. = 1.62
145 facets + 16 facets on girdle = 161
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.350 T/L = 0.350 P/W = 0.431
C/W = 0.206 H/W = (P+C)/W+0.02 = 0.657 P/H = 0.656 C/H = 0.314 Vol./W^3 = 0.211
PAVILION
CROWN
Addition # 12 – Cut this in refractive indexes 1.62 to 2.14 with no changes. This works well in light to medium saturated materials and it should be cut at least 10mm or larger. This is easy to cut and very bright.
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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