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


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

Lens Jeff Graham Facet Design 1 Lens Jeff Graham Facet Design 2

Lens (DOME4.JRG)
By Jeff R. Graham
Copyright 2007
80.6% Light Return
Angles for R.I. = 1.62
133 facets + 12 facets on girdle = 145
12-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.294 T/L = 0.294 P/W = 0.419
C/W = 0.295 H/W = (P+C)/W+0.02 = 0.734 P/H = 0.571 C/H = 0.402 Vol./W^3 = 0.277

Addition # 13 – Cut this in refractive indexes 1.62 to 2.14 with no changes. This is an interesting cut and works well in any light to medium saturated material. This is not hard to cut.

Lens Jeff Graham Facet Design 3

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.