Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Hexed “T” (TLINE23.JRG)
By Jeff R. Graham
Copyright 1995
81.7% Light Return
Angles for R.I. = 1.62
61 facets + 10 facets on girdle = 71
2-fold, mirror-image symmetry
96 index
L/W = 1.203 T/W = 0.606 T/L = 0.503
P/W = 0.451 C/W = 0.218
H/W = (P+C)/W+0.02 = 0.689
P/H = 0.655 C/H = 0.316
Vol./W^3 = 0.348
Gram Book 1 – The P9(G) can be cut in after P4(G) if you want to. The P8,P10 facets only meet at the girdle, so it’s important that you make sure that the girdle is level. Cut in any material, 1-12cts. This works well in Topaz, and Peridot.
Random – Cosine – ISO
Detailed faceting instructions by Jeff Graham available at The Rock Peddler