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


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

 

Thistle (MIR5.JRG) Thistle cut in blue/pink bi color Tourmaline
By Jeff R. Graham
Copyright 2004
90.4% Light Return
Angles for R.I. = 1.62
32 facets + 8 facets on girdle = 40
4-fold, mirror-image symmetry
96 index
L/W = 1.000 P/W = 0.466 C/W = 0.209
H/W = (P+C)/W+0.02 = 0.695
P/H = 0.671 C/H = 0.300
Vol./W^3 = 0.251

Addition # 9 – Note: The P3 cuts just short of center, by varying this tier you will notice that the scissor reflections on the crown will change. This is easy, very fast to cut and works well in any material. I especially like it in Garnets. Cut in refractive indexes 1.62 to 1.93 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.