Reverse “P”: 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 "Reverse "P" ".
Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)
Reverse "P" (TLINE.JRG)
By Jeff R. Graham
Copyright 1994
76.5% Light Return
Angles for R.I. = 1.62
43 facets + 6 facets on girdle = 49
6-fold, mirror-image symmetry
96 index
L/W = 1.155 T/W = 0.559 T/L = 0.485
P/W = 0.442 C/W = 0.213
H/W = (P+C)/W+0.02 = 0.675
P/H = 0.655 C/H = 0.315
Vol./W^3 = 0.263
Gram Book 1 - This design is unusual and not hard to cut. The P3 & P4 facets are a different size which gives the stone a very different flash. P4 facets cut very fast so watch out, 1/2-4cts any color med to light material. This design is surprisingly nice, give it a try… Cut in refractive index 1.62 to 1.93 (77.5%) with no changes.
Random - Cosine - ISO
Detailed faceting instructions by Jeff Graham available at The Rock Peddler
