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


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

Malt Square (B19.JRG)
By Jeff R. Graham
Copyright 1999
90.3% Light Return
Angles for R.I. = 1.62
53 facets + 8 facets on girdle = 61
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.612 T/L = 0.612
P/W = 0.522 C/W = 0.132
H/W = (P+C)/W+0.02 = 0.673
P/H = 0.775 C/H = 0.196
Vol./W^3 = 0.302

Addition # 5 – This cuts easy and works well in a medium colored material. It is not a high crown and works well with saturated materials. Cut this in R.I. 1.62 to 1.76 (86.5%) with no changes.

 


Random – Cosine – ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler