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

Quark (MIR74.JRG)
By Jeff R. Graham
Copyright 2005
87% Light Return
Angles for R.I. = 1.62
37 facets + 16 facets on girdle = 53
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.245 T/L = 0.245 P/W = 0.434
C/W = 0.249 H/W = (P+C)/W+0.02 = 0.703 P/H = 0.618 C/H = 0.354 Vol./W^3 = 0.250

Addition # 10 - Cut in refractive indexes 1.62 to 1.76 with no changes. This is designed for lightly saturated materials. I designed it for some pastel Afghan Tourmaline. It cuts fairly easy and works in about any size. I prefer sizes over 6mm. Note: P5 is cut short and just floats, the tier is not critical. It is done that way to add some interest to the flash, it makes "V" reflections. You can cut it to center point if you wish.

 

 

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