Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)

Opposed Step 3.0 (MC9.JRG)
By Jeff R. Graham
Copyright 1999
91.2% Light Return
Angles for R.I. = 1.62
17 facets + 4 facets on girdle = 21
2-fold, mirror-image symmetry
96 index
L/W = 3.000 T/W = 0.873 T/L = 0.291
P/W = 0.501 C/W = 0.360
H/W = (P+C)/W+0.02 = 0.880
P/H = 0.569 C/H = 0.409
Vol./W^3 = 1.579

Addition # 4 - This L/W is not critical and may be changed without causing any problems. The crown can be raised if you have the rough or if you do not want to cut at 6 degrees. I use 6 degrees and it is not hard to cut, but CARE must be taken. This has great flash along the length. Cut this in R.I. 1.62 to 2.14 (87.9%) without changes.

 

 

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