Gemmological Characteristic of Quartzite Jade "Feizhoucui" and Its Identification

In recent years, a novel gemstone named "Feizhoucui", originated from the Barberton Makhonjwa Mountains in Africa, has emerged in the jewelry market. To date, there have been limited reports on its gemmological characteristics. To investigate the differences between "Feizhoucui" and other types of quartzite jade and to provide a scientific foundation for its identification, our research team collected both rough material and finished product samples of "Feizhoucui". The gemmological characteristics of the samples were studied using conventional gemmological testing instruments, super-resolution microscope, thin section observation under polarized light microscope, scanning electron microscope(SEM), electron microprobe(EPMA), infrared spectroscopy(FITR), Raman spectroscopy, X-ray powder diffraction(XRD) and energy dispersive spectroscopy(EDS) analysis. The results indicated that "Feizhoucui" is a kind of quartzite jade, with α-quartz as the main mineral component, exhibiting a granular structure and forming a compact aggregate of cryptocrystalline-micrystalline quartz. The green inclusions are mainly mica minerals, possibly illite, while metal inclusions are predominantly pyrite. The transparent inclusions are mainly barite. As an emerging gemstone, "Feizhoucui" has great development prospects in the jewelry market and the norms of the commercial and trade market need to be further improved to promote the sustainable and healthy development of the "Feizhoucui" industry in the future.