Faceting Design Diagram: Old Faithful – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

Old Faithful (TLINE59.JRG) 1.98 carat Sunset Tourmaline
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

Gram Faceting Archive of Information
This edited version of an article by the late Jeff Graham is part of a special archived informational series from Gram Faceting. Used with permission.