Star “M”: Faceting Design Diagram

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

Star "M" (SAP12.JRG)
By Jeff R. Graham
Copyright 1995
82.2% Light Return
Angles for R.I. = 1.76
65 facets + 8 facets on girdle = 73
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.544 T/L = 0.544
P/W = 0.442 C/W = 0.218
H/W = (P+C)/W+0.02 = 0.680
P/H = 0.650 C/H = 0.320
Vol./W^3 = 0.261

Gram Book 1 - This design cuts simple and it gives a nice flash in about any color of material. It is nice to use for Montana rough that seems to come in rounded shapes, but not always chunky, 1/2-2cts+. Cut in refractive index 1.78 to 2.14 (83.6%) with no changes.

Random - Cosine - ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler