Faceting Design Diagram: Di-Ag Opposed – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite

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

Di-Ag Opposed (MC12.JRG) 2.75 carat kelly green Tourmaline
By Jeff R. Graham
Copyright 1999
87.1% Light Return
Angles for R.I. = 1.62
18 facets + 4 facets on girdle = 22
2-fold symmetry
96 index
L/W = 1.593 P/W = 0.485 C/W = 0.200
H/W = (P+C)/W+0.02 = 0.704
P/H = 0.688 C/H = 0.283
Vol./W^3 = 0.545

Addition # 4 – This is a nice change of pace, it cuts with no surprises I like it in about any material, especially the darker green crystal Tourmaline. The ends are steep for dark “c” axis. I nick the tips so they are not real sharp. this works in Topaz also… Cut this in R.I. 1.62 to 1.76 without 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.