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


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

Hint Jeff Graham Facet Design Hint Jeff Graham Facet Design

Hint (MC112.JRG)
By Jeff R. Graham
Copyright 2006
75.8% Light Return
Angles for R.I. = 1.62
82 facets + 6 facets on girdle = 88
3-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.364 T/L = 0.364 P/W = 0.530
C/W = 0.198 H/W = (P+C)/W+0.02 = 0.748 P/H = 0.709 C/H = 0.265 Vol./W^3 = 0.236

Addition # 12 – Cut this in refractive indexes 1.62 to 1.93 (79.7%) with no changes. This is designed for light materials and is brighter than the ray trace indicates. The crown can be cut in a different order.

Hint Jeff Graham Facet Design

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.