Faceting Design Diagram: Port of Call – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

Port of Call (MC57.JRG)Zircon cut by Tony Carson
By Jeff R. Graham
Copyright 2002
82.5% Light Return
Angles for R.I. = 1.62
73 facets + 18 facets on girdle = 91
3-fold, mirror-image symmetry
96 index
L/W = 1.048 T/W = 0.488 T/L = 0.465
P/W = 0.493 C/W = 0.211
H/W = (P+C)/W+0.02 = 0.725
P/H = 0.681 C/H = 0.292
Vol./W^3 = 0.246

Addition # 7 – This design is made to be deep for lighter colored materials and has great dispersion. Cut it refractive indexes 1.62 to 1.93 with no changes. I like this in white Zircon


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.