3-Triangle: 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 "3-Triangle".
Sapphire / Corundum (Ruby, Ceylon, Padparadschah, Pink, Yellow, Green)
3-Triangle (SAP17.JRG)
By Jeff R. Graham
Copyright 1998
75% Light Return
Angles for R.I. = 1.76
34 facets + 6 facets on girdle = 40
3-fold, mirror-image symmetry
96 index
L/W = 1.155 T/W = 0.681 T/L = 0.590
P/W = 0.420 C/W = 0.217
H/W = (P+C)/W+0.02 = 0.657
P/H = 0.640 C/H = 0.330
Vol./W^3 = 0.239
Addition # 3 - The crown can be raised as high as 52 or cut as shallow as 42 degrees without changing the light return. This is good for about any material depending on the color. It's good for earrings especially, 1-6cts. Man- made Sapphire and Spinel works…
Random - Cosine - ISO
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
Related Articles
Sapphire Value, Price, and Jewelry Information
Ruby Gemstone Value, Price & Jewelry Insights
Corundum Value, Price, and Jewelry Information
Padparadscha Sapphire Value, Price, and Jewelry Information
Latest Articles
800 Years of Mogok: A Celebration in Tenuous Times
What is the Average Gemstone Faceting Yield?
Pyroxmangite Value, Price, and Jewelry Information
How to Identify Emerald Simulants and Synthetics
Never Stop Learning
When you join the IGS community, you get trusted diamond & gemstone information when you need it.
