Faceting Design Diagram: In-Line Crown – Sapphire / Corundum – Ruby, Ceylon, Padparadschah, Pink, Yellow, Green


Sapphire / Corundum (Ruby, Ceylon, Padparadschah, Pink, Yellow, Green)

In-Line Crown (CRUND1.JRG)
By Jeff R. Graham
Copyright 1993
79.3% Light Return
Angles for R.I. = 1.76
113 facets + 16 facets on girdle = 129
16-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.499 T/L = 0.499
P/W = 0.397 C/W = 0.206
H/W = (P+C)/W+0.02 = 0.623
P/H = 0.637 C/H = 0.331
Vol./W^3 = 0.214

Addition # 3 – This design works well with any Sapphire, in the light to medium dark range, 1/2-8cts. It has a lot of sparkle and is easy to cut. This is mainly for man-made material, but it will certainly work in real Sapphire if you are lucky and have a piece large enough. Cut in refractive indexes 1.73 to 2.14 (85.4%) with no changes.


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.