Color Enhancement by Diffusion of Beryllium in Dark Blue Sapphire

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,sam-ples 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 de-creased.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.Espe-cially,decreased absorption band in the vicinity of 570 nm was responsible for the lighter blue color.There-fore,we confirmed that the dark blue sapphires from China and Australia were changed to vivid blue.