Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)

H&H Crown Rectangle (TLINE5.JRG)
By Jeff R. Graham
Copyright 1993
70.5% Light Return
Angles for R.I. = 1.62
43 facets + 12 facets on girdle = 55
2-fold, mirror-image symmetry
96 index
L/W = 1.450 T/W = 0.712 T/L = 0.491
P/W = 0.440 C/W = 0.212
H/W = (P+C)/W+0.02 = 0.673
P/H = 0.655 C/H = 0.315
Vol./W^3 = 0.373

Gram Book 1 – This design is good for rectangular material and gives a much better light return than the 70.5% that ray traced. It can be cut in another order. It’s not hard to cut and works well in light to med material, this works well in Topaz.

 

 


Random – Cosine – ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler