Standard Round Brilliant with Frosted or Dark Pavilion Star
GemCad Derived Rendering by Bob Keller Bob Keller

SRB Variation with Frosted or Dark Pavilion Star
SRB Variation with Frosted or Dark Pavilion Star
Angles for R.I. = 1.54 65 facets + 16 facets on girdle = 81
8-fold, mirror-image symmetry 96 index
L/W = 1.000 T/W = 0.543 T/L = 0.543 P/W = 0.442 C/W = 0.137 H/W = (P+C)/W+0.02 = 0.600 P/H = 0.738 C/H = 0.229
Vol./W^3 = 0.195 Brightness at 0 degrees tilt for R.I. = 1.54
COS = 64.2% ISO = 68.3%
Pavilion
pb 43.50 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 42.00 96-12-24-36-48-60-72-84 Cut to meet pb,g
f 38.00 06-18-30-42-54-66-78-90 Cut to meet pm,culet
Crown
cb 36.00 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 Cut to meet g - level girdle
cm 31.00 96-12-24-36-48-60-72-84 Cut to meet cb,g
s 18.00 06-18-30-42-54-66-78-90 Cut to meet cb,cm
t 00.00 table Cut to meet s,cm
This variation of the SRB adds an extra course of facets to the pavilion, forming a starburst pattern and adding an embellishing accent at the culet. In the variation illustrated the accent facets are cut below the critical angle so they will intentionally window and create a 'dark star' accent when they are polished. These facets can also be left unpolished to create a frosted effect on the culet accent.


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