Sapphire, as well as most colored gemstones today are routinely treated to improve their appearance and increase their salability. Simple heat application, often called ‘cooking’ is an ancient method of enhancing colored stones. Depending on the stone itself, other forms of enhancement may be applied. Diffusion heats sapphires at a high temperature and adds certain elements to complete the process. But another process has been revealed in the global market and it warrants a separate identification and disclosure to both merchants and the end users.