“B” Oval: Faceting Design Diagram
Information and guide for Faceting Design Diagrams. This facet design is called a " "B" Oval". The P11(G) can be cut in earlier, after cutting the P6(G).
Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
"B" Oval (TLINE22.JRG)
By Jeff R. Graham
Copyright 1995
82.5% Light Return
Angles for R.I. = 1.62
57 facets + 12 facets on girdle = 69
2-fold, mirror-image symmetry
96 index
L/W = 1.203 T/W = 0.542 T/L = 0.450
P/W = 0.460 C/W = 0.229
H/W = (P+C)/W+0.02 = 0.709
P/H = 0.648 C/H = 0.324
Vol./W^3 = 0.317
Addition # 1 - The P11(G) can be cut in earlier if you want to, after cutting the P6(G).The meet point at the P9 apex is cut off when the P12's are cut. The meet is where the P9's form a "V". Cut in refractive indexes 1.62 to 1.93 with no changes. Light to medium material, 1-6cts.
Random - Cosine - ISO
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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