Photoinduced H1b and H1c centers in some natural treated diamonds

Three natural, treated-color diamonds present photoinduced H1b/H1c centers after UV exposure. As the H1b/H1c absorptions increase, that of the 595 nm center decreases. Recovery occurs by simple exposure to a standard incandescent 100 W lamp. The centers implied are all related to nitrogen and to the existence of a treatment, the formation of H1b/H1c centers coming from the trapping of the 595 nm center. The photoinduced behavior seems to confirm the close relation between the 595 nm center and the H1b/H1c centers, and might help in gemological identification.