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

Opposed Beryl (MC10.JRG)
By Jeff R. Graham
Copyright 1999
82% Light Return
Angles for R.I. = 1.56
25 facets + 12 facets on girdle = 37
2-fold, mirror-image symmetry
96 index
L/W = 2.000 T/W = 0.917 T/L = 0.458
H/W = 0.732
Vol./W^3 = 0.751

Addition # 4 - This can be hard to cut the first time. It is a variation on the Vargas opposed bar. I designed it for longer narrow crystals (Tourmaline, Beryl). Establishing the proper L/W with a preform is a good idea. Cut the girdle facets as evenly as you can into thirds, you will probably have to do some adjusting to get this one finished, but it is well worth it. This works well in Tourmaline, and Topaz... Cut this in R.I. 1.56 to 2.14 (86.5%) without changes.

 

 

Random - Cosine - ISO

Return to OnLine Design Index