Faceting Design Diagram: Double Dutch Deep – Tourmaline, Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

Double Dutch Deep Jeff Graham Facet Design 1 Double Dutch Deep Jeff Graham Facet Design 2

Double Dutch Deep (DOME22.JRG)

By Jeff R. Graham
Copyright 2007
79.1% Light Return
Angles for R.I. = 1.62
109 facets + 12 facets on girdle = 121
12-fold symmetry
96 index L/W = 1.000 T/W = 0.341 T/L = 0.341 P/W = 0.419
C/W = 0.325 H/W = (P+C)/W+0.02 = 0.764 P/H = 0.549 C/H = 0.425 Vol./W^3 = 0.309

Addition # 13 – Cut in refractive indexes 1.62 to 2.14 with no changes. Cut this in lightly saturated materials. It works great in light to pale Afghan Tourmaline which is what I designed it for.

Double Dutch Deep 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.