8 Round Brilliant - gem design8 Round Brilliant - gem design

8 Round Brilliant : Faceting Design Diagram

Information and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "8 Round Brilliant"


Quartz (Amethyst, Citrine, Ametrine, Smokey, Rose)

8 Round Brilliant - gem design

8 Round Brilliant (QTZ2.JRG)
By Jeff R. Graham
Copyright 1993
78.5% Light Return
Angles for R.I. = 1.54
57 facets + 16 facets on girdle = 73
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.490 T/L = 0.490
P/W = 0.435 C/W = 0.168
H/W = (P+C)/W+0.02 = 0.623
P/H = 0.698 C/H = 0.270
Vol./W^3 = 0.226

Addition # 1 - This is a pretty standard round brilliant, a nice stone in any size and easy to cut. The crown at 42 degrees is as high as you can go and still have good light return in low R.I. materials. Cut in refractive indexes 1.54 to 1.93 (92.2%) 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.

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