Abstract: Imperial topaz is a kind of precious topaz, whose colour is orange or pink-orange. There has been a wealth of research on topaz, but few studies have been found to systematically characterize the gemmological and spectroscopic characteristics of imperial topaz. In this study, the gemmological and spectral characteristics of imperial topaz were systematically studied by conventional gemmological testing methods, laser ablation inductively coupled plasma mass spectrometer(LA-ICP-MS), Raman spectrometer, infrared spectrometer, three-dimensional fluorescence spectrometer, ultraviolet-visible spectrometer, photoluminescence spectrometer. The refractive index of imperial topaz samples is 1.629-1.641, higher than that of blue or colourless topaz. The fluoresce of imperial topaz is yellow or orange under long wave ultraviolet light and it has medium degree of orange-light orange pleochroism. The infrared spectrum and Raman spectrum of imperial topaz are basically consistent with the standard infrared spectrum and Raman spectrum of topaz. The three-dimensional fluorescence spectrum shows that there are two main fluorescence centers of imperial topaz, which are located at 424 nm(λ_ex)/686 nm(λ_em) and 582 nm(λ_ex)/686 nm(λ_em). Some samples also have a subfluorescence center in the yellow or orange regions of the emission wavelength. The electronic transition of Cr⁴⁺ produces absorption in the UV-Vis spectrum around 420 nm and 530 nm, resulting in the distinctive orange colour of imperial topaz.