Comparison of luminescence lifetimes from natural and laboratory irradiated diamonds

Among gem diamonds, one of the most challenging identifications is distinguishing naturally irradiated diamond from laboratory irradiated diamond. In both cases, the GR1 optical center is created, which in high concentrations imparts a greenish color to the diamond. This research attempted to identify if time-resolved spectroscopy at the nanosecond scale would demonstrate substantive differences between the lifetime behavior of the GR1, in addition to the H3 and NV0 centers due to the type of irradiation. All three centers showed nominally similar behavior and decay times; however, the luminescence decay of treated diamonds showed more complex behavior with additional exponential decay components able to be resolved. To our knowledge, this is the first study directly comparing data derived from natural and laboratory irradiated diamonds, specifically here, the H3, NV0, and GR1 optical centers. (C) 2015 Elsevier B.V. All rights reserved.