12 Swirl: Faceting Design Diagram
Details and information on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts and facets suitable for different gems.
Garnet (Pyrope, Rhodolite, Almandine, Spessartite, Grossular, Demantoid, Tsavorite)
12 Swirl (GNETA2.JRG)
By Jeff R. Graham
Copyright 1993
91.9% Light Return
Angles for R.I. = 1.78
85 facets + 12 facets on girdle = 97
12-fold symmetry
96 index
L/W = 1.000 T/W = 0.362 T/L = 0.362
P/W = 0.369 C/W = 0.180
H/W = (P+C)/W+0.02 = 0.569
P/H = 0.649 C/H = 0.316
Vol./W^3 = 0.203
Addition # 3 - A variation of the 8-Swirl, Almandite Garnet, cuts like the "8" and makes a nice stone, 1-10ct. This works well in man made materials, like YAG, Sapphire and Spinel. I prefer it in lighter colors, it is nice in Zircons too…
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
Garnet Value, Price, and Jewelry Information
How Do Garnets Form?
Garnet Symbolism
Top Spots for Gem Hunting in the US
Latest Articles
Precision Faceting a Story Gemstone: Choosing Rough
32 Green Gemstones (How Many Do You Know?)
A Guide to Antique Georgian Jewelry
Hambergite Value, Price, and Jewelry Information
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!