Faceting Design Diagram: Tri-Angled Triangle – Garnet – Pyrope, Rhodolite, Almandine, Spessartite, Grossular, Demantoid, Tsavorite


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

Tri-Angled Triangle (GNETP18.JRG)
By Jeff R. Graham
Copyright 1993
78.1% Light Return
Angles for R.I. = 1.73
61 facets + 9 facets on girdle = 70
3-fold, mirror-image symmetry
96 index
L/W = 1.071 T/W = 0.517 T/L = 0.483
P/W = 0.429 C/W = 0.193
H/W = (P+C)/W+0.02 = 0.642
P/H = 0.668 C/H = 0.301
Vol./W^3 = 0.217

Gram 1 – This stone has better light return than the 80% that it shows. It works best when it is cut in light material, 1-8cts. This works well in Spinel, Sapphire and YAG.


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.