1910 French Rose Cut Diamond and Lab-Grown Sapphire Ring, Platinum, 18K (sold)

This ring has a spectacular sapphire, which while chemically and visually identical to a natural sapphire, did not grow in the ground. Rather, it more than likely grew in a furnace belonging to a Frenchman named Auguste Verneuil— a chemist who invented a process for making synthetic sapphires in 1902.