Faceting Design Diagram: Pinch – Beryl – Aquamarine, Emerald, Helidore, Bixbite, Goshenite, Morganite, Golden Beryl


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

Pinch (AQUA7.JRG)
By Jeff R. Graham
Copyright 1995
70.8% Light Return
Angles for R.I. = 1.56
71 facets + 8 facets on girdle = 79
2-fold, mirror-image symmetry
96 index
L/W = 1.503 T/W = 0.956 T/L = 0.636
P/W = 0.500 C/W = 0.197
H/W = (P+C)/W+0.02 = 0.717
P/H = 0.697 C/H = 0.275
Vol./W^3 = 0.438

Gram Book 1 – This is a good design for some of those long Beryl crystals. A preform helps, be sure that the 1.50 L/W is right. This design gives nice color and return on crystal shaped rough. This is not easy to cut, 1-12cts. Cut in refractive index 1.56 to 1.76 (75%) 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.