Bygone: Faceting Design Diagram

Sunstone (Feldspar, Bytonite, Labradorite, Spectrolite, Orthoclase)

Bygone (SUN18.JRG)
By Jeff R. Graham
Copyright 2006
77.3% Light Return
Angles for R.I. = 1.54
55 facets + 6 facets on girdle = 61
6-fold, mirror-image symmetry
96 index
L/W = 1.155 T/W = 0.524 T/L = 0.454 P/W = 0.704
C/W = 0.194 H/W = (P+C)/W+0.02 = 0.918 P/H = 0.767 C/H = 0.211 Vol./W^3 = 0.411

PAVILION

CROWN

Addition # 11 - Cut in refractive indexes 1.54 to 2.14 with no changes. This is for light colored materials (no shiller) and it is killer in Beryl. This is pretty easy to cut. It may require a custom setting because of the depth. Note: The girdle can be cut in first and the P1 cut to meet so that center point is not needed and it saves rough.

Detailed faceting instructions by Jeff Graham available at The Rock Peddler