12 Board: Faceting Design Diagram
Details and information on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts and facets suitable for different gems.
12 Board (CHECK9.JRG)
By Jeff R. Graham
89.1% Light Return
Angles for R.I. = 1.54
30 facets + 8 facets on girdle = 38
2-fold, mirror-image symmetry
L/W = 1.250 P/W = 0.450 C/W = 0.243
H/W = (P+C)/W+0.02 = 0.713
P/H = 0.631 C/H = 0.341 Vol./W^3 = 0.435
Addition # 6 - This is fast and bright, notice that there is no table. Cut the C4,C5 as evenly as you can, there is no real meet point on them. I like this in about any material.
Random - Cosine - ISO
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
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