One day in 1952, the Corning Glass Works chemist placed a sample of photosensitive glass inside a furnace and set the temperature to 600 degrees Celsius. At some point during the run, a faulty controller let the temperature climb to 900 degrees C. Expecting a melted blob of glass and a ruined furnace, Stookey opened the door to discover that, weirdly, his lithium silicate had transformed into a milky white plate. When he tried to remove it, the sample slipped from the tongs and crashed to the floor. Instead of shattering, it bounced.
The future National Inventors Hall of Fame inductee didn’t know it, but he had just invented the first synthetic glass-ceramic, a material Corning would later dub Pyroceram. Lighter than aluminum, harder than high-carbon steel, and many times stronger than regular soda-lime glass, Pyroceram eventually found its way into everything from missile nose cones to chemistry labs. It could also be used in microwave ovens, and in 1959 Pyroceram debuted as a line of space-age serving dishes: Corningware.
The material was a boon to Corning’s fortunes, and soon the company launched Project Muscle, a massive R&D effort to explore other ways of strengthening glass. A breakthrough came when company scientists tweaked a recently developed method of reinforcing glass that involved dousing it in a bath of hot potassium salt. They discovered that adding aluminum oxide to a given glass composition before the dip would result in remarkable strength and durability.