11-Sided Brilliant for 96 Index by Charles Covill

No96-11 - designed by Charles Covill ccovill@mindspring.com
Angles for R.I. = 1.71 78 facets + 11 facets on girdle = 89
11-fold, mirror-image symmetry 96 index
L/W = 1.013 T/W = 0.592 T/L = 0.584 P/W = 0.420 C/W = 0.104 H/W = (P+C)/W+0.02 = 0.544 P/H = 0.772 C/H = 0.191
Vol./W^3 = 0.188 Brightness at 0 degrees tilt for R.I = 1.71
COS = 86.6 ISO = 94.0

Pavilion
g1 90.00 96-09-17-26-35-44-52-61-70-79-87 Cut to equal depth, establish size
1 45.00 96-09-17-26-35-44-52-61-70-79-87 Meet g1, make temporary center point
2 39.00 04-13-22-31-39-48-57-65-74-83-92 Meet at permanent center point
3 42.00 01-08-10-16-18-25-27-34-36-43-45-51-53-60-62-69-71-78-80-86-88-95 cut to meet 1,2 - note the meet fudging at indexes 10,16,45,51,80 amd 86
Crown
1 32.00 96-09-17-26-35-44-52-61-70-79-87 cut to meet g1
2 26.00 04-13-22-31-39-48-57-65-74-83-92 Cut to meet g1,1 - note the meet fudging at indexes 13, 48 and 83
3 20.00 04-13-22-31-39-48-57-65-74-83-92 Cut to meet 1,2 - note the meet fudging with the tips of the crown 1 facets at indexes 35, 61 and 96.
t 0.00 Table Table

Stones with a prime number symmetry above 5 (7, 11, 13, 17...) are seen less commonly than those with even numbered symmetry. It requires a special index equally divisible by 11 (such as a 77) to cut a perfectly symmetrical 7 or 11 sided stone. This 11 sided cut is designed for the more common 96 index. It is easy to cut with all of the facets around the same course cut at the same angle. Note the meet point 'fudging' on facets close to the girdle around index 13, 48 and 83.


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