Diffusion of beryllium was performed on dark blue sapphire from China and Australia. The samples were heated with beryllium as a dopant in a furnace at 1 600 ℃ for 42 h in air. After beryllium diffusion, samples were analyzed by UV-Vis, FTIR, and WD-XRF spectroscopy. 　After heat-treatment with Be as a catalyst, the irons of the ferrous state were changed to the ferric state. Therefore, reaction of Fe2+/Ti4+ IVCT was decreased. The absorption peaks at 3 309 cm-1 attributed to OH radical were disappeared completely due to carry out heat treatment.　Consequently, the intensity of absorption band was decreased in the visible region. Especially, decreased absorption band in the vicinity of 570 nm was responsible for the lighter blue color. Therefore, we confirmed that the dark blue sapphires from China and Australia were changed to vivid blue.