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

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

eff Graham Gemstone Facet Design

 Jeff Graham Gemstone Facet Design


Tumbler (MIR78.GJRG)
By Jeff R. Graham
Copyright 2005
80.8% Light Return
Angles for R.I. = 1.62
64 facets + 16 facets on girdle = 80
8-fold symmetry
96 index
L/W = 1.000 P/W = 0.435 C/W = 0.259
H/W = (P+C)/W+0.02 = 0.714 P/H = 0.609 C/H = 0.363
Vol./W^3 = 0.212


Addition # 10 – This is fast and fun to cut, the flash is really very pretty. I prefer this in light saturations. On large stones a table can be cut. Try this in some earrings, they are striking. This is a nice change from a round brilliant.


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.