The colour characteristics, chemical composition and spectroscopic characteristics of the yellow-red “Myanmar huanglongyu” samples were studied through Fourier transform infrared spectrum, laser Raman spectrometer, ultraviolet-visible spectroscopy, an X-ray fluorescence spectrometer, and an X-Rite SP62 hand-held spectrophotometer. The quantitative relationship between the colour and spectral characteristics of “Myanmar huanglongyu” was analyzed. The results show that yellow-red “Myanmar huanglongyu” is mainly composed of SiO2, with small amounts of Fe, Cu, Cr and other transition metal elements, and belongs to the cryptocrystalline quartz jade. There is a high correlation between the lightness and the hue angle of the “Myanmar huanglongyu”, and the change of iron content has a significant effect on the lightness and hue angle of the “Myanmar huanglongyu”. The first derivatives of the ultraviolet-visible absorption spectra can infer the relative contents of goethite and hematite in the “Myanmar huanglongyu”, and the colour of the “Myanmar huanglongyu” changes from yellow to red as the position of the primary wave trough shifts toward the long-wave direction. Under CIE D65 standard light source and N9 Munsell neutral background, using K-Means clustering method, the 32 yellow-red the “Myanmar huanglongyu” were divided into three grades of fancy, fancy intense and fancy deep.