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

"88" Around (MC17.JRG)
By Jeff R. Graham
Copyright 1999
83% Light Return
Angles for R.I. = 1.62
61 facets + 8 facets on girdle = 69
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.531 T/L = 0.531
P/W = 0.445 C/W = 0.182
H/W = (P+C)/W+0.02 = 0.648
P/H = 0.688 C/H = 0.281
Vol./W^3 = 0.228

Addition # 4 - This one is a nice change from a regular "RB". I use it in light to medium material, it is great in pink Tourmaline from Nigeria. It is pretty easy, 2cts+. Works in Topaz and Peridot also... Cut this in R.I. 1.62 to 2.14 (92.1%) without changes.

 

 

 

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