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


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

Stepin Four Jeff Graham Facet Design

 

Stepin Four Jeff Graham Facet Design

Step’in Four (MIR81.JRG)
By Jeff R. Graham
Copyright 2005
87.4% Light Return
Angles for R.I. = 1.62
25 facets + 8 facets on girdle = 33
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.257 T/L = 0.257 P/W = 0.466
C/W = 0.182 H/W = (P+C)/W+0.02 = 0.668 P/H = 0.698 C/H = 0.272 Vol./W^3 = 0.252

 

Addition # 10 – Cut in refractive indexes 1.62 to 1.76 with no changes. This works well in light to medium saturations. I use it for Garnets, particularly for earrings. It’s pretty fast and easy to cut. The reflections will surprise you.

Stepin Four 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.