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


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

Glow (MIR27.JRG)
By Jeff R. Graham
Copyright 2004
91.5% Light Return
Angles for R.I. = 1.62
46 facets + 5 facets on girdle = 51
5-fold, mirror-image symmetry
80 index
L/W = 1.051 T/W = 0.172 T/L = 0.164
P/W = 0.382 C/W = 0.246
H/W = (P+C)/W+0.02 = 0.648
P/H = 0.589 C/H = 0.380
Vol./W^3 = 0.196

Addition # 9 – This is designed for lightly saturated materials like Tourmaline and Aquamarine. Try this in a light Tourmaline nodule, it is a real sparkler. Cut in refractive indexes 1.54 to 2.14 with no changes. The table can be skipped on a small stone.

 

 


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.