Gemmological Characteristic of Demantoid from Pakistan

In this study we used spectroscope, gemstone microscope, Fourier transform infrared spectrometer, ultraviolet-visible spectrophotometer to investigate the characteristics of the composition and inclusion in demantoid from Pakistan. Based on the experiments, the result indicates that the infrared spectrum of Pakistani demantoid and the infrared spectrum of andradite have the same characteristics. The ultraviolet test result shows that in addition to the absorption of 443 nm (Fe) and 618 nm (Cr), Pakistani demantoid has a characteristic absorption of 732 nm, Raman test results show that the black opaque inclusions in Pakistani demantoid are magnetite.