Prime Construct: Faceting Design Diagram

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

Prime Construct (MIR75.JRG)
By Jeff R. Graham
Copyright 2005
86.5% Light Return
Angles for R.I. = 1.62
37 facets + 12 facets on girdle = 49
4-fold, mirror-image symmetry
80 index
L/W = 1.000 T/W = 0.491 T/L = 0.491 P/W = 0.450
C/W = 0.190 H/W = (P+C)/W+0.02 = 0.661 P/H = 0.681 C/H = 0.288 Vol./W^3 = 0.259

PAVILION

CROWN

Addition # 10 - Cut in refractive indexes 1.62 to 1.76 with no changes. This is designed for light to medium saturated stones and is very nice. It is simple and fast to cut, but the flash is intense.

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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