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


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

Framed Star (B5.JRG)
By Jeff R. Graham
Copyright 1999
85% Light Return
Angles for R.I. = 1.62
75 facets + 14 facets on girdle = 89
2-fold, mirror-image symmetry
96 index
L/W = 1.330 T/W = 0.839 T/L = 0.631
P/W = 0.621 C/W = 0.166
H/W = (P+C)/W+0.02 = 0.807
P/H = 0.770 C/H = 0.205
Vol./W^3 = 0.429

Addition # 5 – Cut to meet C5,C8. A preform is a good idea. Cut to center point then cut the girdle to meet P1, establishing shape, then breaks. Cut in R.I. 1.62 to 1.93 with no changes. On a smaller stone C11 can be left off…


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.