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Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Hor-I-zon Sun (MC29.JRG)
By Jeff R. Graham
Copyright 1998
89.8% Light Return
Angles for R.I. = 1.62
61 facets + 19 facets on girdle = 80
1-fold, mirror-image symmetry
96 index
L/W = 1.012 T/W = 0.528 T/L = 0.521
P/W = 0.410 C/W = 0.159
H/W = (P+C)/W+0.02 = 0.589
P/H = 0.696 C/H = 0.271
Vol./W^3 = 0.171Addition # 4 - This is a neat one to try for a change of pace. It is not really hard to cut and because it is based on a round it has very good light return. The reflection looks like rays, cut in a larger size 2cts+. This works in Topaz and Peridot. Cut this in R.I. 1.62 to 1.76 without changes.

Random - Cosine - ISO
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