Bill Bray

Bill Bray

Bill Bray
Bill is a diamond cutter with thirty years of experience. He was formally trained in the only accredited trade school at the time, the American School of Diamond Cutting. He was one of only a few who completed the three one year courses. He is a college graduate and has launched his W.R.Bray Cut Scoring System for Modern Brilliant Cut Diamonds (patent pending) also known as BrayScore®. He is a frequent contributor on the Polygon Trading Network. He has been a self-employed diamond cutter since 1977.

Last 5 articles of this author

Upper Halves – Counter Point

Fri, 25 Mar 2005

The opening paragraph of the article presents a concept that indexing top halves produces different amount of weight retention. This is correct, although not as dramatic as presented. A diamond cutter knows that brilliandeering an entire diamond calls for a weight loss of approximately 4%. This causes one to question the facts presented in the conclusion of this article Setting a Constant Girdle Thickness at the Mains which shows a range of finished weights from .866 cts. (Index 3) to .774 cts. (Index 1) or 11%. As noted, these findings are outside the parameters of realistic cutting. The results presented in the article were accurate when they concluded that a fraction of a point was lost by cutting the top halves in different configurations (stating that the Index 1 stone was .817cts. VS the Index 3 stone of .808cts.), but the results change upon further examination of indexing with relation to diameter, and then change more so in setting constant girdle thickness at the mains, which in a normally cut stone is not a product indexing the upper girdle halves. Girdle thickness can only be increased by adding more girdle (read reducing the diameter of the stone) either by bruting or faceting or polishing.

Read More...