Today, all eyes are on the newly-minted Duke and Duchess of Cambridge as they tie the royal knot. Millions now know that Kate Middleton wears Princess Diana’s famous sapphire and diamond engagement ring. But far fewer know that, starting in the 1950s, GE’s research scientists began developing near-gemstone quality synthetic diamonds – albeit for industrial purposes.
A press release from the GE Research Laboratory in Schenectady, New York dated February 15, 1955, reads: “Man-made diamonds, the climax to a 125-year effort to duplicate nature’s hardest and most glamorous substance, were displayed here today.” The excitement wasn’t overstated: Before GE’s breakthrough, the idea of creating Earth’s hardest substance in the lab seemed like an impossibility.
How did they do it? The GE team built an ultrahigh-pressure apparatus, called the “Diamond Press,” structured to concentrate and sustain tremendous pressure in a small area. A donut-sized chamber was surrounded by conical pistons that produced 1.5 million pounds per square inch and 5000 degrees Fahrenheit. In the chamber, metal and carbon were given what the scientists called a “diamond whammy” — an electrical jolt that melted the metal-carbon mixture and precipitated the diamond crystallization process. Ten to 20 minutes later, when the apparatus was shut down, a man-made diamond sat in the chamber.
The initial GE diamonds were the first man-made substance to scratch other diamonds, and the first production runs resulted in diamonds of up to one-tenth of a carat — perhaps not princess-ready, but promising for industrial applications like cutting and polishing in manufacturing. To prove to skeptics that the GE diamonds, while synthetic, had all the characteristics of the original, scientists demonstrated with x-rays that their creations had crystal structures identical to diamonds and were composed of carbon.
GE’s synthetic diamonds found several applications over the years, from a durable stylus for record players sold by GE’s consumer electronics business to sharper and stronger cutting blades for industrial saws.
In 2010, GE’s diamond-makers, Herbert Strong, Francis Bundy, Robert Wentorf and H. Tracy Hall, were inducted into the National Inventors Hall of Fame.