Faceting Design Diagram: “S” Hex – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

“S” Hex (TLINE10.JRG) 2.40 carat champange Tourmaline
By Jeff R. Graham
Copyright 1994
83.2% Light Return
Angles for R.I. = 1.62
49 facets + 6 facets on girdle = 55
6-fold, mirror-image symmetry
96 index
L/W = 1.155 T/W = 0.589 T/L = 0.510
P/W = 0.430 C/W = 0.196
H/W = (P+C)/W+0.02 = 0.647
P/H = 0.665 C/H = 0.304
Vol./W^3 = 0.251

Gram Book 1 – A fairly standard hex to cut, it has a very nice-star-in-a-star flash and a good light return. Any material in light to medium color is good, I cut this quite often, because Tourmaline crystals are often this shape. Cut in refractive index 1.62 to 2.14 (84.8%) 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.