Delta: Faceting Design Diagram
Detailed information and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Delta".
Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Delta (CHECK56.JRG)
By Jeff R. Graham
Copyright 2002
86.8% Light Return
Angles for R.I. = 1.62
46 facets + 9 facets on girdle = 55
3-fold, mirror-image symmetry
96 index
L/W = 1.021 T/W = 0.290
|T/L = 0.284 P/W = 0.417 C/W = 0.221
H/W = (P+C)/W+0.02 = 0.657
P/H = 0.634 C/H = 0.336
Vol./W^3 = 0.226
Addition # 8 - The crown is deep and I generally cut this in light colors, although it will work well in medium colored material too. This is nice in Zambian Tourmaline nodules.
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
Mint Tourmalines: Gemstones for Our Times
Tourmaline Engagement Ring Stones: the Ultimate Guide
How Do Tourmalines Form?
Latest Articles
Peridot Value, Price, and Jewelry Information
Traditional Diamond Cut Grading Methods
Cutting a 294-ct Trilliant Morganite: An Interview with Steve Moriarty
Tourmaline Engagement Ring Stones: the Ultimate 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!