Faceting Design Diagram: 72 Brilliant – Tourmaline, Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

72 Brilliant Graham Facet Design 1 72 Brilliant Graham Facet Design 2

72 Brilliant (DOME35.JRG)
By Jeff R. Graham
Copyright 2007
82.1% Light Return
Angles for R.I. = 1.62
64 facets + 9 facets on girdle = 73
9-fold, mirror-image symmetry
72 index
L/W = 1.015 T/W = 0.221 T/L = 0.218 P/W = 0.417 C/W = 0.326
H/W = (P+C)/W+0.02 = 0.763 P/H = 0.547 C/H = 0.427
Vol./W^3 = 0.257

Addition # 13 – Cut in refractive indexes 1.62 to 2.14 with no changes. This is easy to cut and works well in light to medium saturated material. This is a nice cut for Tourmaline nodules.

72 Brilliant Graham Facet Design 3

Detailed faceting instructions by Jeff Graham available at The Rock Peddler