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


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

Seagull Cut (GNETP19.JRG)
By Jeff R. Graham
Copyright 1994
78.7% Light Return
Angles for R.I. = 1.73
43 facets + 6 facets on girdle = 49
3-fold, mirror-image symmetry
96 index
L/W = 1.155 T/W = 0.516 T/L = 0.447
P/W = 0.432 C/W = 0.222
H/W = (P+C)/W+0.02 = 0.674
P/H = 0.641 C/H = 0.329
Vol./W^3 = 0.265

Gram Book 1 – This cut is unusual because of the 3/3 split symmetry on the table. It cuts fast and makes a nice 13 ct. stone for earrings or rings. This works in man-made Sapphire and Spinel… Cut in refractive indexes 1.73 to 2.14 (81%) 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.