Old Faithful: Faceting Design Diagram

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

Old Faithful (TLINE59.JRG)
By Jeff R. Graham
Copyright 1998
84% Light Return
Angles for R.I. = 1.62
57 facets + 16 facets on girdle = 73
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.454 T/L = 0.454
P/W = 0.431 C/W = 0.185
H/W = (P+C)/W+0.02 = 0.636
P/H = 0.678 C/H = 0.291
Vol./W^3 = 0.207

Addition # 2 - This is still about one of the best cuts there is as far as I am concerned. Cut in refractive indexes 1.62 to 2.14 (92.2%) with no changes.

Random - Cosine - ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler