Standard Round Brilliant with Pavilion Star (Zircon Cut)
GemCad Derived Rendering by Bob Keller Bob Keller

SRB Variation with Pavilion Star (Zircon Cut)
SRB Variation with Pavilion Star (Zircon Cut)
Angles for R.I. = 1.54 73 facets + 16 facets on girdle = 89
8-fold, mirror-image symmetry 96 index
L/W = 1.000 T/W = 0.516 T/L = 0.516 P/W = 0.462 C/W = 0.218 H/W = (P+C)/W+0.02 = 0.700 P/H = 0.660 C/H = 0.311
Vol./W^3 = 0.236 Brightness at 0 degrees tilt for R.I. = 1.54
COS = 41.1% ISO = 46.6%
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
z 41.00 02-10-14-22-26-34-38-46-50-58-62-70-74-82-86-94 Cut to meet pm,culet
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 96-12-24-36-48-60-72-84 Cut to meet cb,g
s 27.00 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 at the culet, forming a starburst pattern and adding an embellishing accent. In the variation illustrated the accent facets are split vertically, and it is often referred to as the 'Zircon Cut' variation of the SRB.


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