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


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

Crystal Tourmaline (TLINE8.JRG) Tourmaline cut by Tony Carson
By Jeff R. Graham
Copyright 1994
81.0% Light Return
Angles for R.I. = 1.62
43 facets + 9 facets on girdle = 52
3-fold, mirror-image symmetry
96 index
L/W = 1.073 T/W = 0.467 T/L = 0.435
P/W = 0.441 C/W = 0.177
H/W = (P+C)/W+0.02 = 0.638
P/H = 0.692 C/H = 0.277
Vol./W^3 = 0.241

Gram Book 1 – This design is a nice one. It works great for material that has this shape on the “C” axis. It should be cut in a little larger size, and any color that has good light through the “C”, 1-6cts. This works very well cut in the Nigerian pink Tourmaline. Cut in refractive index 1.62 to 1.93 (83.6%) 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.