“CC” Triangle: Faceting Design Diagram
Information and guide for Faceting Design Diagrams. This design is called a " "CC" Triangle". Roughing in the table before you cut the C5 is a good idea.
Beryl (Aquamarine, Emerald, Helidore, Bixbite, Goshenite, Morganite, Golden Beryl)
"CC" Triangle (AQUA6.JRG)
By Jeff R. Graham
Copyright 1995
70.8% Light Return
Angles for R.I. = 1.56
67 facets + 12 facets on girdle = 79
3-fold, mirror-image symmetry
96 index
L/W = 1.017 T/W = 0.633 T/L = 0.622
P/W = 0.439 C/W = 0.174
H/W = (P+C)/W+0.02 = 0.633
P/H = 0.693 C/H = 0.275
Vol./W^3 = 0.223
Gram Book 1 - Roughing in the table before you cut the C5 is a good idea. If you rough in the corners P4, C5(not final) it will help get a straight girdle. This is not easy to cut, you may have to adjust some angles, 1-12cts. Cut in refractive index 1.56 to 1.76 (79.8%) 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
Aquamarine Value, Price, and Jewelry Information
Emerald Value, Price, and Jewelry Information
Seven Famous Emeralds and Their Stories
Emerald Origins: History and Identification
Latest Articles
21 Pink Gemstones (How Many Do You Know?)
How Does Topaz Form?
Sphene (Titanite) Value, Price, and Jewelry Information
Citrine 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!