Flat Top Opal: 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 "Flat Top Opal".

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Opal (Jelly, Cherry, Orange, Clear)

Flat Top Opal (OPAL1.JRG)
By Jeff R. Graham
Copyright 1998
82% Light Return
Angles for R.I. = 1.45
89 facets + 16 facets on girdle = 105
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.513 T/L = 0.513
P/W = 0.479 C/W = 0.171
H/W = (P+C)/W+0.02 = 0.669
P/H = 0.715 C/H = 0.255
Vol./W^3 = 0.251

Addition # 2 - Opal is hard to get any flash out of. The crown is pretty flat to help improve light return. Any good color 2-12cts. Cut in refractive indexes 1.45 to 1.93 (88.2%) with no changes. This design will work well in Moldavite.


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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