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


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

Sparkles (B24.JRG)
By Jeff R. Graham
Copyright 2001
87.1% Light Return
Angles for R.I. = 1.62
85 facets + 6 facets on girdle = 91
6-fold, mirror-image symmetry
96 index
L/W = 1.155 T/W = 0.448 T/L = 0.388
P/W = 0.488 C/W = 0.256
H/W = (P+C)/W+0.02 = 0.764
P/H = 0.639 C/H = 0.335
Vol./W^3 = 0.336

Addition # 5 – This needs to be cut in light material to get the best effect. It has a lot of life and works very well in Danburite. The crown can be hard to cut on a smaller stone because there are a lot of facets that need to meet. This works in R.I. 1.62 to 1.93 (87.5%) 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.