Science Past from issue of January 14, 1961
MAN-MADE DIAMONDS ONE-CARAT SIZE PRODUCED — Large, man-made diamonds, more than a carat in size, have been produced for the first time. The diamonds are dark in color and cannot now be used for industrial purposes because of structural imperfections. They were made at the General Electric Research Laboratory, Schenectady, N. Y., where the first man-made diamonds were also made. Small man-made diamonds have been perfected to the point where they are superior to natural diamonds for many uses. These small diamonds are used for cutting, grinding and polishing. Industry uses carat-size diamonds for drills, dressing tools, dies and single point cutting tools. The major source of natural diamonds is the Congo.