Faceting Design Diagram: 4X Square – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

4X Square (TLINE12.JRG)
By Jeff R. Graham
Copyright 1994
81.6% Light Return
Angles for R.I. = 1.62
53 facets + 12 facets on girdle = 65
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.479 T/L = 0.479
P/W = 0.450 C/W = 0.198
H/W = (P+C)/W+0.02 = 0.669
P/H = 0.673 C/H = 0.297
Vol./W^3 = 0.267

Gram Book 1 – Here is a nice modified square that cuts fast and has a very nice flash. It can be cut in about any size or material, 1/2-6cts. Cut in refractive index 1.62 to 2.14 (83.8%) with no changes.

 

 


Random – Cosine – ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler

About the author
Jeff R. Graham
The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.
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