Tang: Faceting Design Diagram
Successful tips, details and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Tang".
Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Tang (MIR39.JRG)
By Jeff R. Graham
Copyright 2004
91.5% Light Return
Angles for R.I. = 1.62
31 facets + 9 facets on girdle = 40
3-fold, mirror-image symmetry
96 index
L/W = 1.038 T/W = 0.407 T/L = 0.393
P/W = 0.412 C/W = 0.200
H/W = (P+C)/W+0.02 = 0.632
P/H = 0.652 C/H = 0.317
Vol./W^3 = 0.201
Addition # 9 - This is very bright and is ideal for light to medium saturated materials. It yields great for "c" axis Tourmaline. Cut in refractive indexes 1.62 to 1.76 with no changes. This is fast to cut and looks great. Hint: The P5 can be cut at a little lower angle and makes interesting reflections.
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
Tourmaline Value, Price, and Jewelry Information
Difficult Gemstone Separations
Gemstone Examination Lesson
Green Tourmaline (Verdelite) Buying Guide
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!