Faceting Design Diagram: Glass Triangle – Quartz – Citrine, Amethyst, Ametrine, Smokey, Rose

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

Glass Triangle (QTZ22.JRG)
By Jeff R. Graham
Copyright 1993
80% Light Return
Angles for R.I. = 1.54
67 facets + 12 facets on girdle = 79
3-fold, mirror-image symmetry
96 index
L/W = 1.003 T/W = 0.433 T/L = 0.432
P/W = 0.447 C/W = 0.198
H/W = (P+C)/W+0.02 = 0.666
P/H = 0.672 C/H = 0.298
Vol./W^3 = 0.202

Gram Book 1 – This triangle is medium to hard to cut, it has a lot of meet points. The Pavilion has a lot of long narrow facets at different angles, which gives the stone a lot of sparkle. Light to med material, 1-16cts. A larger stone is easier to cut. This works well in Tourmaline and Topaz.


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.