Purple Cross: Faceting Design Diagram
Successful tips and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Purple Cross".
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
Jeff R. Graham
The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.
Related Articles
Tanzanite (Zoisite) Value, Price, and Jewelry Information
Exploring the Hidden World of Tanzanite Mining: A Journey into the Depths of Tanzania
Ten Gemstones Rarer than Diamond
What is Gemstone Pleochroism?
Latest Articles
Sodalite Value, Price, and Jewelry Information
What are the Best Rough Sapphire Stones?
Advice for Determining Gemstone Value
Raw Stone Jewelry Design and Care
Never Stop Learning
When you join the IGS community, you get trusted diamond & gemstone information when you need it.
Get Gemology Insights
Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!