Faceting Design Diagram: Two Spin Star – Quartz – Citrine, Amethyst, Ametrine, Smokey, Rose


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

Two Spin Star (QTZ29.JRG) 2.15 carat Iolite
By Jeff R. Graham
Copyright 1994
92.8% Light Return
Angles for R.I. = 1.54
30 facets + 6 facets on girdle = 36
6-fold symmetry
96 index
L/W = 1.155 P/W = 0.450 C/W = 0.164
H/W = (P+C)/W+0.02 = 0.635
P/H = 0.709 C/H = 0.259
Vol./W^3 = 0.215

Gram Book 1 – This design cuts easy and fast. When you get to C3 use a fine lap and cut gently. It is a nice design for about any material and I usually cut it in 4-8mm sizes. I designed it for earrings. On larger stones a table should be cut to meet C2,C3. I recommend this because as the stone gets larger there is a “hole” at the apex (look at the ray trace). Cut in refractive index 1.54 to 2.14 (86.5%) 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.