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


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

Spokes (MC46.JRG)
By Jeff R. Graham
Copyright 2000
93.2% Light Return
Angles for R.I. = 1.62
49 facets + 12 facets on girdle = 61
6-fold, mirror-image symmetry
96 index
L/W = 1.059 T/W = 0.327 T/L = 0.308
P/W = 0.447 C/W = 0.179
H/W = (P+C)/W+0.02 = 0.646
P/H = 0.692 C/H = 0.277
Vol./W^3 = 0.220

Addition # 7 – I designed this for medium saturated material and use it for earrings. The spokes show up on the crown nicely. This works well in Garnet and Sapphire with no 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.