Tabby: Faceting Design Diagram

Quartz (Amethyst, Citrine, Ametrine, Smokey, Rose)

Tabby (B8.JRG)
By Jeff R. Graham
Copyright 1999
78.4% Light Return
Angles for R.I. = 1.54
79 facets + 18 facets on girdle = 97
3-fold, mirror-image symmetry
96 index
L/W = 1.005 T/W = 0.591 T/L = 0.588
P/W = 0.515 C/W = 0.139
H/W = (P+C)/W+0.02 = 0.674
P/H = 0.765 C/H = 0.206
Vol./W^3 = 0.238

Addition # 5 - This cuts nicly in a large Quartz or Topaz. Cut P1 to center point, then cut the girdle to meet, then cut in the breaks. The light ray trace is misleading, it is really a bright stone, especially in light material. This is 91.2% in R.I. 1.62 with no changes…

Random - Cosine - ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler