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


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

Atlas (MC65.JRG) Blue Tourmaline
By Jeff R. Graham
Copyright 2002
87.6% Light Return
Angles for R.I. = 1.62
57 facets + 12 facets on girdle = 69
2-fold, mirror-image symmetry
96 index
L/W = 1.330 T/W = 0.598 T/L = 0.449
P/W = 0.555 C/W = 0.230
H/W = (P+C)/W+0.02 = 0.804
P/H = 0.690 C/H = 0.286
Vol./W^3 = 0.400

Addition # 7 – This is great for medium saturated materials. It works well in Garnet, Sapphire and man-made materials with no changes. Note: I rough in P1, P2, P3 at 41.64 and then cut the other angles on a finer lap.


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.