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


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

Circle Graham Facet Design 1 Circle Graham Facet Design 2

Circle (DOME36.JRG)
By Jeff R. Graham
Copyright 2007
75.7% Light Return
Angles for R.I. = 1.62
73 facets + 8 facets on girdle = 81
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.211 T/L = 0.211 P/W = 0.438 C/W = 0.401
H/W = (P+C)/W+0.02 = 0.859 P/H = 0.510 C/H = 0.467
Vol./W^3 = 0.323

Addition # 13 – Cut in refractive indexes 1.62 to 2.14 with no changes. This is designed to help improve lightly saturated rough. I designed it for Afghan Tourmaline nodules, but it works well in any pale to light saturated rough.

Circle Graham Facet Design 3

Detailed faceting instructions by Jeff Graham available at The Rock Peddler

About the author
Jeff R. Graham
The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.
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