Faceting Design Diagram: 3-Corner Triangle – Quartz – Citrine, Amethyst, Ametrine, Smokey, Rose

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

3-Corner Triangle (QTZ15.JRG)
By Jeff R. Graham
Copyright 1993 7
79.2% Light Return
Angles for R.I. = 1.54
46 facets + 12 facets on girdle = 58
3-fold, mirror-image symmetry
96 index
L/W = 1.038 T/W = 0.595 T/L = 0.573
P/W = 0.418 C/W = 0.188
H/W = (P+C)/W+0.02 = 0.626
P/H = 0.668 C/H = 0.300
Vol./W^3 = 0.230

Gram Book 1 – Be very careful cutting P5, P6, they cut fast. This triangle has a lot of sparkle because of the size difference of P5, P6. It’s a little harder to cut than it looks 1-8cts. This also works very well in Tourmaline and jewelers like it because it is very easy to set. I use this design as one of my standard trillions. Cut in refractive index 1.54 to 2.14 (82.8%) 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.