Faceting Design Diagram: 12 Swirl – Garnet – Pyrope, Rhodolite, Almandine, Spessartite, Grossular, Demantoid, Tsavorite


Garnet (Pyrope, Rhodolite, Almandine, Spessartite, Grossular, Demantoid, Tsavorite)

12 Swirl (GNETA2.JRG)
By Jeff R. Graham
Copyright 1993
91.9% Light Return
Angles for R.I. = 1.78
85 facets + 12 facets on girdle = 97
12-fold symmetry
96 index
L/W = 1.000 T/W = 0.362 T/L = 0.362
P/W = 0.369 C/W = 0.180
H/W = (P+C)/W+0.02 = 0.569
P/H = 0.649 C/H = 0.316
Vol./W^3 = 0.203

Addition # 3 – A variation of the 8-Swirl, Almandite Garnet, cuts like the “8” and makes a nice stone, 1-10ct. This works well in man made materials, like YAG, Sapphire and Spinel. I prefer it in lighter colors, it is nice in Zircons too…

 


Random – Cosine – ISO

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.