Luminescence Characteristic and Fluorescence Spectrum of HPHT-Treated and Irradiated Diamond

Fluorescence images and spectra were collected from HPHT-treated or irradiated diamonds with different colour by GV5000 and DiamondView^TM. Combining with the photoluminescence spectra, the results showed that the luminescence characteristics of the diamonds with same treated method is consistent. HPHT-treated diamonds of type Ⅰa revealed yellowish green fluorescence, and peaked at 460, 520 nm in fluorescence spectra. Irradiated diamonds of type Ⅰa revealed blue fluorescence, and peaked at 450 nm in fluorescence spectra, with some 830, 884 nm weak peaks. Irradiated CVD synthetic diamonds revealed green to brownish green fluorescence, and showed peaks at 488, 620, 741, 786, 895 nm. The diamonds with the same colour by different treatment can be distinguished by luminescence observation and fluorescence spectra.