F35 Fighter Jet Sapphire

F-35 fighter jets use sapphire windows to cover their high-tech sensor arrays - in fact, each fighter jet uses over 200 pounds of sapphire. The Air Force gave Rubicon a grant to build a furnace and grow the biggest single crystal sapphire windows in the world for these jets (with a record-shattering size of over three feet long and 18 inches wide). During the development process, some of the crystals cracked and some came out contaminated, and those were stored in the factory until it was closed and we won them at auction. While these crystals may not have been military grade, they have a chance to retire as gems instead.