Faceting Design Diagram: 8-Swirl – Garnet – Pyrope, Rhodolite, Almandine, Spessartite, Grossular, Demantoid, Tsavorite


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

8-Swirl (GNETA1.JRG)
By Jeff R. Graham
Copyright 1993
90.9% Light Return
Angles for R.I. = 1.78
57 facets + 8 facets on girdle = 65
8-fold symmetry
96 index
L/W = 1.000 T/W = 0.403 T/L = 0.403
P/W = 0.375 C/W = 0.141
H/W = (P+C)/W+0.02 = 0.536
P/H = 0.699 C/H = 0.263
Vol./W^3 = 0.198

Gram Book 1 – A nice design for colored Garnet (notice the 1.78 R.I). It is a little different to cut. The facets cut fast, watch out. I prefer this design in a light Garnet like a Mali. Cut in refractive index 1.78 to 2.14 (92.6%) with no changes.


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.