Faceting Design Diagram: Tourmaline 20 – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

Tourmaline 20 (MC32.JRG) 1.87 carat Tourmaline
By Jeff R. Graham
Copyright 1998
83.6% Light Return
Angles for R.I. = 1.62
43 facets + 8 facets on girdle = 51
2-fold, mirror-image symmetry
96 index
L/W = 2.000 T/W = 1.354 T/L = 0.677
P/W = 0.493 C/W = 0.181
H/W = (P+C)/W+0.02 = 0.694
P/H = 0.710 C/H = 0.261
Vol./W^3 = 0.744

Addition # 4 – If you are cutting in Tourmaline, be sure that the “c” axis is close in color to the a/b or this design will get muddy. The keel on this is harder than it looks, it works well in Topaz, 1-12cts. Cut this in R.I. 1.62 to 1.76 (82.4%) without 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.