Faceting Design Diagram: “Streeeech” – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite

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

“Streeeech” (TLINE62.JRG)
By Jeff R. Graham
Copyright 1998
72% Light Return
Angles for R.I. = 1.62
31 facets + 4 facets on girdle = 35
2-fold, mirror-image symmetry
96 index
L/W = 4.000 T/W = 3.491 T/L = 0.873
P/W = 0.602 C/W = 0.229
H/W = (P+C)/W+0.02 = 0.851
P/H = 0.707 C/H = 0.269
Vol./W^3 = 1.972

Addition # 2 – This works best on open “c” axis Tourmaline. A preform is needed 4.0 L/W. The crown can be cut as low as 32 degrees (10 degrees off of all the crown tiers), 2-18cts.


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.