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


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

The Ring (B22.JRG)
By Jeff R. Graham
Copyright 2000
81% Light Return
Angles for R.I. = 1.62
69 facets + 16 facets on girdle = 85
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.470 T/L = 0.470
P/W = 0.512 C/W = 0.209
H/W = (P+C)/W+0.02 = 0.741
P/H = 0.691 C/H = 0.282
Vol./W^3 = 0.319

Addition # 5 – This is pretty easy to cut and should be done in a light material because it darkens quite a bit. I like this in light colored Tourmaline or Topaz. There are a lot of trapped rays, which show up as a very nice dispersion pattern in the finished stone. This is really nice in Danburite and works well in man-made materials. Cut this in R.I. 1.62 to 1.76 (84.9%) 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.