Faceting Design Diagram: Little Block – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


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

Little Block (TLINE35.JRG)
By Jeff R. Graham
Copyright 1996
84.4% Light Return
Angles for R.I. = 1.62
45 facets + 8 facets on girdle = 53
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.356 T/L = 0.356
P/W = 0.423 C/W = 0.297
H/W = (P+C)/W+0.02 = 0.740
P/H = 0.572 C/H = 0.401
Vol./W^3 = 0.301

Addition # 1 – This design is for those chunky pieces of rough that are really too square to cut a round out of. I designed it for that light pastel Afghan Tourmaline that is available once and a while (it will help darken color). It cuts easy and the crown facets can be brought down a few degrees, if needed, 1/2-8cts (finished). Cut in refractive indexes 1.62 to 1.76 with no changes. This works best in light colored material.

 


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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