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


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

Diamond Star (CHECK31.JRG)
By Jeff R. Graham
Copyright 2001
87% Light Return
Angles for R.I. = 1.62
49 facets + 6 facets on girdle = 55
16-fold, mirror-image symmetry
120 index
L/W = 1.143 T/W = 0.321 T/L = 0.281
P/W = 0.517 C/W = 0.193
H/W = (P+C)/W+0.02 = 0.730
P/H = 0.709 C/H = 0.264
Vol./W^3 = 0.257

Addition # 6 – L/W is critical on this one, otherwise the diamonds on the top can be a pain to line up. Other than that it cuts easily and is a very unusual design.


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.