Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Prime Construct (MIR75.JRG)
By Jeff R. Graham
Copyright 2005
86.5% Light Return
Angles for R.I. = 1.62
37 facets + 12 facets on girdle = 49
4-fold, mirror-image symmetry
80 index
L/W = 1.000 T/W = 0.491 T/L = 0.491 P/W = 0.450
C/W = 0.190 H/W = (P+C)/W+0.02 = 0.661 P/H = 0.681 C/H = 0.288 Vol./W^3 = 0.259
PAVILION
CROWN
Addition # 10 – Cut in refractive indexes 1.62 to 1.76 with no changes. This is designed for light to medium saturated stones and is very nice. It is simple and fast to cut, but the flash is intense.
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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