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

The Ring (B22.JRG)
By Jeff R. Graham
Copyright 2000
81% Light Return
Angles for R.I. = 1.62
69 facets + 16 facets on girdle = 85
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.470 T/L = 0.470
P/W = 0.512 C/W = 0.209
H/W = (P+C)/W+0.02 = 0.741
P/H = 0.691 C/H = 0.282
Vol./W^3 = 0.319

Addition # 5 - This is pretty easy to cut and should be done in a light material because it darkens quite a bit. I like this in light colored Tourmaline or Topaz. There are a lot of trapped rays, which show up as a very nice dispersion pattern in the finished stone. This is really nice in Danburite and works well in man-made materials. Cut this in R.I. 1.62 to 1.76 (84.9%) with no changes.

 

 

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