Faceting Design Diagram: Cut Corner Pent – Garnet – Pyrope, Rhodolite, Almandine, Spessartite, Grossular, Demantoid, Tsavorite


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

Cut Corner Pent (GNETP32.JRG)
By Jeff R. Graham
Copyright 1996
87.1% Light Return
Angles for R.I. = 1.73
66 facets + 10 facets on girdle = 76
5-fold, mirror-image symmetry
80 index
L/W = 1.051 T/W = 0.468 T/L = 0.445
P/W = 0.436 C/W = 0.197
H/W = (P+C)/W+0.02 = 0.653
P/H = 0.668 C/H = 0.301
Vol./W^3 = 0.235

Gram Book 1 – Note 80 index. This cuts easy in about any material, 1-6cts. This works well in man-made Sapphire and Spinel. I especially like it in Rhodolite Garnet 2-3cts. Cut in refractive indexes 1.73 to 2.14 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.