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