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