Faceting Design Diagram: Tour/Top RB – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

Tour/Top RB (TLINE58.JRG)
By Jeff R. Graham
Copyright 1998
82% Light Return
Angles for R.I. = 1.62
73 facets + 16 facets on girdle = 89
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.482 T/L = 0.482
P/W = 0.430 C/W = 0.187
H/W = (P+C)/W+0.02 = 0.637
P/H = 0.675 C/H = 0.293
Vol./W^3 = 0.213

Addition # 3 – This is a pretty standard round brilliant, I cut this design quite a bit and think it is still one of the best. A lot of people have asked me for more “RB” designs so here is a good one. Cut in refractive indexes 1.62 to 2.14 (92.8%) 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.