Checker Square Cushion
GemCad Ray Traces for RI = 1.54
Random Model Cosine Model ISO Model
GemCad Ray Traces for RI = 1.72
Random Model Cosine Model ISO Model
Checker Square Cushion
Designed by Bob Keller - November 2001 Bob Keller
A Bright Cut for Medium to Deep Color Material - Cut as Given for Quartz through CZ
Angles for R.I. = 1.54 56 facets + 16 facets on girdle = 72
4-fold, mirror-image symmetry 96 index
L/W = 1.000 P/W = 0.428 C/W = 0.171H/W = (P+C)/W+0.02 = 0.619 P/H = 0.692 C/H = 0.276
Vol./W^3 = 0.212 Brightness at 0 degrees tilt for RI = 1.54 COS = 77.5 ISO = 86.6
Brightness at 0 degrees tilt for RI = 1.72 COS = 78.2 ISO = 88.0
Pavilion
1 41.00 02-22-26-46-50-70-74-94 Cut to centerpoint - make temp culet
2 40.26 04-20-28-44-52-68-76-92 Meet at centerpoint
g1 90.00 02-22-26-46-50-70-74-94 Match 1, establish lower girdle line
g2 90.00 04-20-28-44-52-68-76-92 Meet g1.1.2
3 40.40 03-21-27-45-51-69-75-93 Meet 1.g1.g2.2 and at culet
Crown
a 45.23 02-22-26-46-50-70-74-94 Match g1, establish upper girdle line
b 47.31 04-20-28-44-52-68-76-92 Meet a.g1.g2
c 21.59 12-36-60-84 Meet b.g2.g2.b
d 17.26 07-17-31-41-55-65-79-89 Meet a.b.c
e 11.00 12-36-60-84 Meet d.c.d

A Checker Square Cushion Design File is available for GemCad users.


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© Bob's Rock Shop Bob Keller