synthetic diamond, General Electric, gems

Examines the cutting behaviour and identifying properties of General Electric’s early gem-quality synthetic diamonds. Cutting trials by Lazare Kaplan & Sons produced well-polished stones but revealed strong directional differences in polishing resistance and substantial weight loss in brilliant cuts. Microscopic dust-like inclusions, ultraviolet fluorescence and phosphorescence, and electrical conductivity provide evidence for distinguishing the colourless, yellow and blue synthetics from natural diamonds. Comparative tables summarize their properties.