“B” Oval: Faceting Design Diagram
Detailed information and guide for Faceting Design Diagrams. This facet design is called a " "B" Oval". The breaks are high, but this should be easy to set.
Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
"B" Oval (B6.JRG)
By Jeff R. Graham
Copyright 1999
80% Light Return
Angles for R.I. = 1.62
81 facets + 16 facets on girdle = 97
2-fold, mirror-image symmetry
96 index
L/W = 1.303 T/W = 0.762 T/L = 0.585
P/W = 0.588 C/W = 0.199
H/W = (P+C)/W+0.02 = 0.807
P/H = 0.728 C/H = 0.247
Vol./W^3 = 0.402
Addition # 5 - The breaks are high, but this should be easy to set on the short ends. Cut to center point, then girdle to meet P1, then breaks. Cut in R.I 1.62 to 1.76 (89.4%) with no changes, light material is best.
Random - Cosine - ISO
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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