Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Nimble (DOME9.JRG)
By Jeff R. Graham
Copyright 2007
84% Light Return
Angles for R.I. = 1.62
73 facets + 8 facets on girdle = 81
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.159 T/L = 0.159 P/W = 0.397
C/W = 0.315 H/W = (P+C)/W+0.02 = 0.733 P/H = 0.542 C/H = 0.431 Vol./W^3 = 0.255
PAVILION
CROWN
Addition # 13 – This is pretty fast to cut and deep to help darken light material. This works in R.I. 1.62to 1.76 with no changes. I designed this for pastel Afghan nodules and it yields well for the shape.
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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