Faceting Design Diagram: Universal Oval 2 – Apatite – Yellow, Green, Neon, Blue


Apatite (Yellow, Green, Neon, Blue)

Universal Oval 2 (APAT1.JRG)
By Jeff R. Graham
Copyright 1998
79% Light Return
Angles for R.I. = 1.64
57 facets + 16 facets on girdle = 73
2-fold, mirror-image symmetry
96 index
L/W = 1.249 T/W = 0.657 T/L = 0.526
P/W = 0.483 C/W = 0.174
H/W = (P+C)/W+0.02 = 0.677
P/H = 0.713 C/H = 0.257
Vol./W^3 = 0.285

Addition # 2 – This works best in Peridot, Spinel, Garnet, and Sapphire. Cut a preform L/W to 1.25, then P1,P3,P5 are center point, the P7 is just short, hence the preform. This cut is pretty standard, 1-16cts. Cut in refractive indexes 1.64 to 2.14 (83.4%) 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.