Standard Round Brilliant with Unstacked Mains
GemCad Derived Rendering by Bob Keller
SRB Variation with Unstacked Mains Angles for R.I. = 1.54 57 facets + 16 facets on girdle = 73 8-fold, mirror-image symmetry 96 index L/W = 1.000 T/W = 0.477 T/L = 0.477 P/W = 0.466 C/W = 0.218 H/W = (P+C)/W+0.02 = 0.704 P/H = 0.662 C/H = 0.309 Vol./W^3 = 0.236 Brightness at 0 degrees tilt for R.I. = 1.54
COS = 39.1% ISO = 44.2%
Pavilion pb 45.00 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 Cut to temporary center point g 90.00 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 Cut to meet pb pm 43.00 96-12-24-36-48-60-72-84 Cut to meet pb,g Crown cb 47.00 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 Cut to meet g - level girdle cm 42.00 06-18-30-42-54-66-78-90 Cut to meet cb,g s 27.00 96-12-24-36-48-60-72-84 Cut to meet cm,cb t 0.00 Table Cut to meet s,cm Another fundamental variation of the SRB 'unstacks' the pavilion and crown main facets, which are cut on the same indexes and 'stacked' in the classic version. This variation has no doubt been accidentally executed more than a few times by faceters who intended to cut the stacked version and somehow got off a cog when they aligned after transferring the stone.
The SRB with Unstacked Mains Design File is available for GemCad users.