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".

Home Learning Center Jewelry and Lapidary Gemstone Faceting Diagrams and Technical Cutting InformationFlat Top Opal: Faceting Design Diagram

By Jeff R. Graham

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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Flat Top Opal: Faceting Design Diagram

Jeff R. Graham

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