Faceting Design Diagram: Square Barb – Garnet – Pyrope, Rhodolite, Almandine, Spessartite, Grossular, Demantoid, Tsavorite


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

Square Barb (GNETP35.JRG)
By Jeff R. Graham
Copyright 1997
92.5% Light Return
Angles for R.I. = 1.73
57 facets + 8 facets on girdle = 65
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.390 T/L = 0.390
P/W = 0.410 C/W = 0.158
H/W = (P+C)/W+0.02 = 0.588
P/H = 0.697 C/H = 0.269
Vol./W^3 = 0.231

Addition # 3 – A nice cut for most Garnet, it’s not very hard, but watch the C6. On a smaller stone it will have to be hand cut, or left out. Cut in size 1-8cts. Cut in refractive indexes 1.73 to 2.14 (92.1%) 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.