Faceting Design Diagram: Shadow Box Triangle – Garnet – Pyrope, Rhodolite, Almandine, Spessartite, Grossular, Demantoid, Tsavorite


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

Shadow Box Triangle (GNETA4.JRG)
By Jeff R. Graham
Copyright 1993
80% Light Return
Angles for R.I. = 1.78
46 facets + 9 facets on girdle = 55
3-fold, mirror-image symmetry
96 index
L/W = 1.012 T/W = 0.312 T/L = 0.308
P/W = 0.416 C/W = 0.187
H/W = (P+C)/W+0.02 = 0.622
P/H = 0.668 C/H = 0.300
Vol./W^3 = 0.210

Gram Book 1 – This design is a little harder to cut (like most triangles), but it has much better return than any other that I’ve ever seen (notice the 1.78 R.I.). Most only have return in the center none in edges. Light to med material this works well in YAG, Sapphire and Spinel, 1-12cts.


Random – Cosine – ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler

About the author
Jeff R. Graham
The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.
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