Faceting Design Diagram: Odd Round n’ Round – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

Odd Round n’ Round (TLINE1.JRG)
By Jeff R. Graham
Copyright 1993
83.4% Light Return
Angles for R.I. = 1.62
129 facets + 16 facets on girdle = 145
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.489 T/L = 0.489
P/W = 0.426 C/W = 0.157
H/W = (P+C)/W+0.02 = 0.603
P/H = 0.707 C/H = 0.260
Vol./W^3 = 0.217

Addition # 2 – This design is for light to med material, 1-16cts. It has a nice uneven sparkle in every direction and is fun to cut because of it’s odd symmetry. Cut in refractive indexes 1.54 to 2.14 (91.4%) 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.