“A” Dome: Faceting Design Diagram

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

"A" Dome (DOME8.JRG)
By Jeff R. Graham
Copyright 2007
89.7% Light Return
Angles for R.I. = 1.62
61 facets + 8 facets on girdle = 69
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.473 T/L = 0.473 P/W = 0.405
C/W = 0.240 H/W = (P+C)/W+0.02 = 0.665 P/H = 0.609 C/H = 0.361 Vol./W^3 = 0.247

PAVILION

CROWN

Addition # 13 - Cut this in refractive indexes 1.62 to 2.14 with no changes. This works well in any lightly saturated material. I designed it for light Afghan nodules.

Detailed faceting instructions by Jeff Graham available at The Rock Peddler