Faceting Design Diagram: Flat Top Opal – Opal – Jelly, Cherry, Orange, Clear


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

Gram Faceting Archive of Information
This edited version of an article by the late Jeff Graham is part of a special archived informational series from Gram Faceting. Used with permission.