H. Tracy Hall, an inventor who in 1954 was a key part of a pioneering scientific team at General Electric that made the first synthetic diamonds, died July 25 in Provo, Utah. He was 88.

Hall’s death was confirmed by a spokesman for the Industrial Diamond Association of America, a trade organization.

At the Research Laboratory of GE in Schenectady, N.Y., Hall and his team used a powerful hydraulic press to subject carbon to extreme pressures and create a sample of tiny octahedral diamonds. In the process, the scientists had also heated the carbon to about 5,000 degrees Fahrenheit and reconfigured its molecular structure.

The result, which was later successfully repeated, was the fruit of three years of experimentation and several centuries of speculation.