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


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

Nigerian Pink (MC40.JRG)Rubellite Tourmaline
By Jeff R. Graham
Copyright 1999
76.5% Light Return
Angles for R.I. = 1.62
52 facets + 15 facets on girdle = 67
3-fold, mirror-image symmetry
96 index
L/W = 1.016 T/W = 0.707 T/L = 0.696
P/W = 0.384 C/W = 0.163
H/W = (P+C)/W+0.02 = 0.567
P/H = 0.677 C/H = 0.288
Vol./W^3 = 0.198

Addition # 4 – This is designed for light colored stones, it has a lot of sparkle and depth for improving dispersion and color. The light return on this is better than the ray trace says, and it has a very nice pattern, 1cts+. 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.