A Round Cushion

GemCad Ray Traces for RI = 1.76
Random Model	Cosine Model	ISO Model

A Round Cushion Designed by Charles W. Covill covill@email.msn.com
Angles for R.I. = 1.76	49 facets + 16 facets on girdle = 65
4-fold, mirror-image symmetry	96 index
L/W = 1.000 T/W = 0.557 T/L = 0.557 P/W = 0.469 C/W = 0.140	H/W = (P+C)/W+0.02 = 0.629 P/H = 0.746 C/H = 0.222
Vol./W^3 = 0.230	Brightness at 0 degrees tilt for RI = 1.64 COS = 58.4 ISO = 70.6

Pavilion
1	45.00	02-22-26-46-50-70-74-94	Cut to meet at false culet.
2	43.83	06-18-30-42-54-66-78-90	Cut to meet with 1 at false culet.
g2	90.00	06-18-30-42-54-66-78-90	Complete level girdle line.
3	41.00	08-16-32-40-56-64-80-88	Meet 2 at girdle,make new culet.
Crown
g1	90.00	02-22-26-46-50-70-74-94	Determine size of stone.
1	32.21	96-24-48-72	Establish girdle thickness.
2	35.00	02-22-26-46-50-70-74-94	Meet 1 at girdle,continue level girdle
3	35.00	06-18-30-42-54-66-78-90	Meet 1 & 2,complete level girdle.
4	29.00	12-36-60-84	Meet 1,2 & 3. Also meet 3 at girdle.
t	0.00	Table
With g1 cut 8 equal sides, Determine size of stone. Cut pavilion facets 1 & 2 to meet at false culet. Cut g2 to complete level girdle line. Cut pavilion facet 3 to meet girdle and form new culet.

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