But in this new study, researchers found a way around that by removing the container altogether. They developed a production method called aerodynamic levitation. If that sounds like a magician's party trick, the real process is equally awesome—the glass and alumina mixture is held in the air as it forms, during which oxygen gas is pumped between the mixture and the surfaces of its container. Then, a laser acts as a spatula, mixing it as it cools. The resulting material contains more alumina than any other glass to date, and the researchers found it to be transparent and reflective. Most importantly, tests showed that the glass was very hard—harder than other oxidized glasses and most metals, and almost as hard as steel, Phys.org reports.