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Topaz (Swiss, Electric, London Blue, Imperial, White, Yellow, Pink, Champange)
Blue Star (TOPAZ3.JRG)
By Jeff R. Graham
Copyright 1993
82.5% Light Return
Angles for R.I. = 1.62
67 facets + 6 facets on girdle = 73
6-fold, mirror-image symmetry
96 index L/W = 1.155 T/W = 0.562 T/L = 0.486
P/W = 0.459 C/W = 0.213
H/W = (P+C)/W+0.02 = 0.692
P/H = 0.663 C/H = 0.308
Vol./W^3 = 0.279Gram Book 1 - Here is a good design for Topaz with sparkle that is easy to cut. It makes good earrings especially in blue material, 1/2-6cts. Cut in refractive index 1.62 to 2.14 (87.9%) with no changes.

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