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


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

Foiled (MC79.JRG)
By Jeff R. Graham
Copyright 2002
91.6% Light Return
Angles for R.I. = 1.62
67 facets + 12 facets on girdle = 79
6-fold, mirror-image symmetry
96 index
L/W = 1.073 T/W = 0.416 T/L = 0.388
P/W = 0.430 C/W = 0.209
H/W = (P+C)/W+0.02 = 0.658
P/H = 0.653 C/H = 0.317
Vol./W^3 = 0.237

Addition # 7 – This is nice, easy to cut and has a fancy look to it when finished. Cut in refractive indexes 1.62 to 1.93 with no changes. This is very good for light to medium saturated materials.


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.