Montana Burst: Faceting Design Diagram
Successful tips and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Montana Burst".
Sapphire / Corundum (Ruby, Ceylon, Padparadschah, Pink, Yellow, Green)
Montana Burst (SAP10.JRG)
By Jeff R. Graham
Copyright 1995
80.2% Light Return
Angles for R.I. = 1.76
57 facets + 8 facets on girdle = 65
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.503 T/L = 0.503
P/W = 0.405 C/W = 0.199
H/W = (P+C)/W+0.02 = 0.624
P/H = 0.649 C/H = 0.318
Vol./W^3 = 0.238
Gram Book 1 - I designed this cut for some nice roundish Montana material that I bought. It cuts easy and makes a nice 1ct+ stone. Cut the steps on the crown to your taste, varied widths are better, I think. Cut in refractive index 1.78 to 1.93 (80.1%) 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
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
How to Identify Synthetic Rough in Gemstone Parcels
Standard Gem Sizes Chart: Guide to Gemstone Dimensions
Alexandrite Value, Price, and Jewelry Information
10 Gemstones Rarer than Diamond: The Earth’s Scarcest Treasures
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!