|Sun Twist - designed by Keith Sanker 07-29-98|
|Angles for R.I. = 1.76||33 facets + 8 facets on girdle = 41|
|8-fold symmetry||96 index|
|L/W = 1.000 T/W = 0.596 T/L = 0.596 P/W = 0.454 C/W = 0.097||H/W = (P+C)/W+0.02 = 0.571 P/H = 0.796 C/H = 0.169|
|Vol./W^3 = 0.203||Brightness at 0 degrees tilt for R.I. = 1.76
COS = 87.1 ISO = 94.1
|1||43.00||96-12-24-36-48-60-72-84||Create center point|
|G1||90.00||96-12-24-36-48-60-72-84||Set stone size, level girdle|
|2||41.00||02-14-26-38-50-62-74-86||Meet G1-1-1-G1, new center point|
|A||30.00||96-12-24-36-48-60-72-84||Set girdle height, level girdle.|
|T||00.00||Table||Cut a 60% table, leave short of B-A-B.|
Shown at left is a colorized GemRay image to give an impression of what the design looks like.
Sun Twist is simple, quick cutting, highly regular, but non-symmetrical octagonal design. It's the pavilion mains that are "twisted" two indexes from where they "should" be that creates a more interesting optical effect. The design is very bright, over 95% ISO at RI 1.62, so it will work even for darker stones.
This design will work great for lower RI material like topaz or beryl and higher RIs as well.
This design typically looks best on small or medium stones because of the limited number of facets.
This design is easy to cut because there are no compounding problems - no meets that define meets that define meets. You can get a good looking well cut stone time after time.
Pavilion cutting goes smoothly - merely cut to a point, make a level girdle and bring the mains down to the girdle. The mains cut fast so go easy.
Cutting the crown is similarly easy. Cut a level girdle and then extend the sun rays to the girdle. The table floats to whatever size pleases your eye (or the rough allows). My eye likes a table about 60% of the stone's width.
Have fun cutting your own Sun Twist!
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