Faceting Design Diagram: Purple Cross – Tanzanite – Zoisite, Thulite


Tanzanite (Zoisite, Thulite)

Purple Cross (TANZ5.JRG)
By Jeff R. Graham
Copyright 1993
82.7% Light Return
Angles for R.I. = 1.69
69 facets + 12 facets on girdle = 81
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.499 T/L = 0.499
P/W = 0.445 C/W = 0.220
H/W = (P+C)/W+0.02 = 0.685
P/H = 0.650 C/H = 0.321
Vol./W^3 = 0.279

Addition # 3 – This design is good for lighter colored material (it will help darken) and has good flash. It is easy to cut and does not take a lot of time, 1 -6cts(good luck on finding clean Tanzanite in 6cts). This works in Peridot as well as Garnet too… Cut in refractive indexes 1.69 to 2.14 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.