Faceting Design Diagram: Step’in Boxes – Tourmaline, Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite

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

Stepin boxes Jeff Graham Facet Design

Jeff Graham Facet Design

Step’in Boxes (MIR84.JRG)
By Jeff R. Graham
Copyright 2005
86.6% Light Return
Angles for R.I. = 1.62
33 facets + 8 facets on girdle = 41
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.257 T/L = 0.257 P/W = 0.438
C/W = 0.229 H/W = (P+C)/W+0.02 = 0.687 P/H = 0.637 C/H = 0.334 Vol./W^3 = 0.278

Addition # 10 – Cut in refractive indexes 1.62 to 1.76 with no changes. This is a good Garnet cut and also works well in about any light to medium saturated stone. Note: P3 floats and can vary to fit rough. I usually cut them to look like the diagram.

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.