Diamond Back: Faceting Design Diagram

Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)

Diamond Back (CHECK72.JRG)
By Jeff R. Graham
Copyright 2003
81.5% Light Return
Angles for R.I. = 1.62
27 facets + 6 facets on girdle = 33
2-fold, mirror-image symmetry
96 index
L/W = 1.33 T/W = 0.590 T/L = 0.457
P/W = 0.418 C/W = 0.146
H/W = (P+C)/W+0.02 = 0.584
P/H = 0.716 C/H = 0.250
Vol./W^3 = 0.217

Addition # 8 - Cut in refractive indexes 1.54 (78.4%) to 2.14 with no changes. This is a neat one, named after a local varmit we have in Tucson in the summer- time (rattlesnakes). This cuts fast and is good in about any material. The L/W on this can vary a bit with no problem.

Random - Cosine - ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler