Diamond “C”: Faceting Design Diagram

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

Diamond "C" (GNETP29.JRG)
By Jeff R. Graham
Copyright 1996
90.3% Light Return
Angles for R.I. = 1.73
57 facets + 10 facets on girdle = 67
2-fold, mirror-image symmetry
96 index
L/W = 1.290 T/W = 0.557 T/L = 0.432
P/W = 0.406 C/W = 0.189
H/W = (P+C)/W+0.02 = 0.614
P/H = 0.660 C/H = 0.307
Vol./W^3 = 0.305

Gram Book 1 - This is a little tough to cut, but well worth it. The P7 & P9 meet at an apex and might need to be cheated a little bit. As long as they are close the P10 will cover them, good for darker material, 2-12cts. This works in man-made Sapphire and Spinel.

Random - Cosine - ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler