Scribe Triangle: Faceting Design Diagram

Successful tips and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Scribe Triangle".


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

Scribe Triangle (TLINE4.JRG)
By Jeff R. Graham Copyright 1993
79.1% Light Return
Angles for R.I. = 1.62
49 facets + 9 facets on girdle = 58
3-fold, mirror-image symmetry
96 index
L/W = 1.020 T/W = 0.360 T/L = 0.353
P/W = 0.424 C/W = 0.182
H/W = (P+C)/W+0.02 = 0.625
P/H = 0.677 C/H = 0.291
Vol./W^3 = 0.207

Gram Book 1 - Cut this design in medium to light material. A larger size stone works best because of the narrow crown facets. It cuts easy and fast for a triangle, and has nice sparkle, 1-12cts. Cut in refractive index 1.62 to 1.76 (79.4%) with no changes.



Random - Cosine - ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler

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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