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

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

Royal Mine (CHECK63.JRG)
By Jeff R. Graham
Copyright 2003
87.4% Light Return
Angles for R.I. = 1.62
61 facets + 8 facets on girdle = 69
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.372
T/L = 0.372 P/W = 0.441 C/W = 0.182
H/W = (P+C)/W+0.02 = 0.643
P/H = 0.686 C/H = 0.282
Vol./W^3 = 0.234

Addition # 8 – This one is really neat. I have always liked an antique/mine cut and this one with a diamond top is cool. Cut in refractive indexes 1.62 to 2.14 (89.7%) with no changes. This works in about any material.


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.