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


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

Seven Rattle Jeff Graham Facet Design 1 Seven Rattle Jeff Graham Facet Design 2

Seven Rattle (DOME32.JRG)
By Jeff R. Graham
Copyright 2007
87.8% Light Return
Angles for R.I. = 1.62
71 facets + 7 facets on girdle = 78
7-fold, mirror-image symmetry
77 index
L/W = 1.026 T/W = 0.410 T/L = 0.399 P/W = 0.398 C/W = 0.339
H/W = (P+C)/W+0.02 = 0.757 P/H = 0.525 C/H = 0.448
Vol./W^3 = 0.280

Addition # 13 – Cut this in refractive indexes 1.62 to 2.14 with no changes. This is unusual and because it is seven-sided, it will need a custom setting. It has a lot of flash and looks very unusual when cut.

Seven Rattle Jeff Graham Facet Design 3

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.