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


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

Twinkle (MIR40.JRG)
By Jeff R. Graham
Copyright 2004
86% Light Return
Angles for R.I. = 1.62
40 facets + 6 facets on girdle = 46
3-fold, mirror-image symmetry
96 index
L/W = 1.155 T/W = 0.385 T/L = 0.334
P/W = 0.397 C/W = 0.212
H/W = (P+C)/W+0.02 = 0.630
P/H = 0.631 C/H = 0.337
Vol./W^3 = 0.239

Addition # 9 – This is not hard to cut, but the meets can be a little tough from a technical standpoint. This works well in any material. Cut in refractive indexes 1.62 to 1.76 with no changes. This is nice in Garnet.


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.