Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Inca Dome (DOME21.JRG)
By Jeff R. Graham
Copyright 2007
85.6% Light Return
Angles for R.I. = 1.62
81 facets + 16 facets on girdle = 97
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.277 T/L = 0.277 P/W = 0.405 C/W = 0.319
H/W = (P+C)/W+0.02 = 0.744 P/H = 0.544 C/H = 0.429
Vol./W^3 = 0.247
PAVILION
CROWN
Addition # 13 – Cut in refractive indexes 1.62 to 2.14 with no changes. This is nice and works well in light to mediumly saturated materials. I like it in mint and fancy colored Garnets as well.
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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