Standard Round Brilliant with 6 Fold Symmetry
GemCad Derived Rendering by Bob Keller
SRB Variation with 6 Fold Symmetry and Split Crown Mains Angles for R.I. = 1.54 49 facets + 12 facets on girdle = 61 6-fold, mirror-image symmetry 96 index L/W = 1.000 T/W = 0.352 T/L = 0.352 P/W = 0.435 C/W = 0.194 H/W = (P+C)/W+0.02 = 0.649 P/H = 0.670 C/H = 0.299 Vol./W^3 = 0.206 Brightness at 0 degrees tilt for R.I. = 1.54
COS = 62.6% ISO = 68.7%
Pavilion pb 43.00 04-12-20-28-36-44-52-60-68-76-84-92 Cut to temporary center point g 90.00 04-12-20-28-36-44-52-60-68-76-84-92 Cut to meet pb pm 41.00 96-16-32-48-64-80 Cut to meet pb,g Crown cb 38.00 04-12-20-28-36-44-52-60-68-76-84-92 Cut to meet g - level girdle cm1 32.00 08-24-40-56-72-88 Cut to meet cb,g cm2 28.00 08-24-40-56-72-88 Cut to meet cb,cm1 s 18.00 96-16-32-48-64-80 Cut to meet cb,cm1,cm2 t 0.00 Table Cut to meet s,cm2 This variation of the SRB decreases the number of facets in each course by 25% by decreasing the symmetry from 8 fold to 6 fold. Decreasing the number of facets decreases the scintillation and is a way of scaling down the SRB to work with smaller stones. This variation also employs unstacked, horizontally split crown mains.
The SRB with 6 Fold Symmetry Design File is available for GemCad users.