Gamma Brilliant

Gemcad by Jeff Ford

Master stone USFG 2008 competition

Your first thought will be 12 mm out of a corundum boule? I found no problem with it as the 44.54 break facets are reasonably low to cut a CAM off of. If you think your boule is not thick enough use a preform of 30 degrees to set your girdle. I found this not necessary though. The finished stone has a total height of 7.1 mm so if your boule is over 9 mm you should be able to cut the 12 mm width.

The only problem on the pavilion side I encountered was that when I was polishing the breaks I manipulated the polish with the cheater and this affected my final meet point at the culet. If I was to cut the stone again I would polish the breaks until they came out even at the finish without manipulating the girdle line. All meets were excellent except the culet. I could have spent a couple hours fixing this but I am just test cutting the stone.

I transferred the stone and my girdle line met with no adjustment telling me I did a good job on hitting center point when I cut the pavilion. When you cut your star facets in watch out for unequal facets. Most cutters pay very little attention to unequal facets. Just look the whole stone over occasionally and you can spot this.

Test cut OK by Art Kavan

Co-Chair USFG Competition Committee

Jeff Ford