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


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

Triple Star (TLINE14.JRG)
By Jeff R. Graham
Copyright 1993
78.5% Light Return
Angles for R.I. = 1.62
113 facets + 16 facets on girdle = 129
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.535 T/L = 0.535
P/W = 0.423 C/W = 0.185
H/W = (P+C)/W+0.02 = 0.628
P/H = 0.673 C/H = 0.295
Vol./W^3 = 0.221

Gram Book 1 – This design is good for a large stone 1-20cts, in light to medium material. It is not hard to cut, and it has a lot of sparkle. The star in the point of the Pavilion makes the table lively. Cut in refractive index 1.62 to 2.14 (89.5%) 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.