Today's market contains large quantities of flame-melting synthetic spinel， which cannot be effectively identified by conventional methods alone. To accurately identify natural and flame-melting synthetic spinels， we used Fourier transform infrared spectroscopy， X-ray fluorescence spectroscopy， absorption spectroscopy， and laser Raman spectroscopy to study the molecular structures， chemical compositions， and color mechanisms of the spinel specimens. The full-width-at-half-maximum （FWHM） was obtained by Lorentz fitting of the 405 cm^-1 peak in the Raman spectrum and analyzed by one-way ANOVA（analysis of variance）. Although the conventional gemological characteristics of natural spinel and flame-melting synthetic spinel were almost identical， there are significant differences in molecular structures， chemical compositions， color mechanisms， and FWHMs. The results provide a theoretical basis for distinguishing natural spinel from flame-melting synthetic spinel.