Faceting Design Diagram: “CC” Triangle – Beryl – Aquamarine, Emerald, Helidore, Bixbite, Goshenite, Morganite, Golden Beryl


Beryl (Aquamarine, Emerald, Helidore, Bixbite, Goshenite, Morganite, Golden Beryl)

“CC” Triangle (AQUA6.JRG)
By Jeff R. Graham
Copyright 1995
70.8% Light Return
Angles for R.I. = 1.56
67 facets + 12 facets on girdle = 79
3-fold, mirror-image symmetry
96 index
L/W = 1.017 T/W = 0.633 T/L = 0.622
P/W = 0.439 C/W = 0.174
H/W = (P+C)/W+0.02 = 0.633
P/H = 0.693 C/H = 0.275
Vol./W^3 = 0.223

Gram Book 1 – Roughing in the table before you cut the C5 is a good idea. If you rough in the corners P4, C5(not final) it will help get a straight girdle. This is not easy to cut, you may have to adjust some angles, 1-12cts. Cut in refractive index 1.56 to 1.76 (79.8%) 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.