Abstract: The pink hydrogrossular samples were tested by conventional gemmological tests, X-ray powder diffraction spectrometer(XRD), Fourier infrared spectroscopy(FTIR), polarizing microscope, microscopic UV-Vis spectrometer and energy dispersive X-ray fluorescence spectrometer (EDXRF), to analyze their chemical compositions, mineral components, microstructures and possible colour origins. The results of X-ray powder diffraction test showed that the pink hydrogrossular samples are composed of hydrogrossular and vesuvianite, and the results of polarizing microscopic test showed that the main mineral hydrogrossular is in granular shape and showing different concentrations of pink by microamplification. A small amount of vesuvianite is in fibrous shape scattered in the inside of the pink hydrogrossular with the colour of brown green under the microscopic observation.According to the results of polarized light microscope, microscopic UV-Vis spectroscopy and EDXRF, the pink colour of the hydrogrossular samples is related to trace elements Fe and Mn, and Mn is the main colour cause.