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

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

Miner (B9.JRG)
By Jeff R. Graham
Copyright 1999
90.3% Light Return
Angles for R.I. = 1.62
65 facets + 16 facets on girdle = 81
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.641 T/L = 0.641
P/W = 0.502 C/W = 0.184
H/W = (P+C)/W+0.02 = 0.706
P/H = 0.711 C/H = 0.261
Vol./W^3 = 0.314

Addition # 5 – This is a “Money Cut”… I have designed this to be simple and adapt- able. The crown can be floated in, notice the lack of meet points. This will help recover weight because of the Barion shape and still be easy and fast. Cut this in light materials because it darkens a bit. Cut P1 to center point, then cut the girdle to meet, then the breaks. This can be cut in R.I. 1.62 to 1.76 (90.2%) 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.