Home Rough Bargains Equipment Books Online Designs Just Ask Jeff Order News List Contact Me Links
Amethyst Aquamarine Beryl Citrine Emerald Garnet Opal Peridot Sapphire Scapolite Spinel Sunstone Topaz Tourmaline Quartz Zircon
Beginner's Page New Stuff Odds & Ends Specials Parcels Synthetics
Cut Gemstones Gemological Information Gemstone Pricing Guides How to buy Gemstones

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

H&H Crown Rectangle (TLINE5.JRG)
By Jeff R. Graham
Copyright 1993
70.5% Light Return
Angles for R.I. = 1.62
43 facets + 12 facets on girdle = 55
2-fold, mirror-image symmetry
96 index
L/W = 1.450 T/W = 0.712 T/L = 0.491
P/W = 0.440 C/W = 0.212
H/W = (P+C)/W+0.02 = 0.673
P/H = 0.655 C/H = 0.315
Vol./W^3 = 0.373

Gram Book 1 - This design is good for rectangular material and gives a much better light return than the 70.5% that ray traced. It can be cut in another order. It's not hard to cut and works well in light to med material, this works well in Topaz.

 

 



Random - Cosine - ISO

Return to OnLine Design Index

Home Rough Bargains Equipment Books Online Designs Just Ask Jeff Order News List Contact Me Links


Copyright 1998-2007 Gram Faceting - All Rights Reserved.