[The chemical and structural analysis of Tibetan medicine Fanshi]

The element and microstructure of Tibetan medicine Fanshi were investigated, in order to explore the material basis of Fanshi. X-ray fluorescence spectroscope (XRF), inductively coupled plasma optical emission spectrometer (ICP-OES) and X-ray diffraction (XRD) were used to assay the Fanshi samples from different Tibetan regions. XRF and ICP-OES analysis showthat the main elements in Fanshi are Ca, O and C, but also contain some kinds of minor elements, such as Mg, Al, Na, Si, K, Ag, Ba, Fe, Mn, S, Sr, Zn and so on. XRD analysis shows that the main material structures in Fanshi are (Mg(x)Ca(1-x))CO3 (rhombohedral, R-3c) and CaCO3 (rhombohedral, R-3c), but also exists a small quantity of CaCO3 (orthorhombic, Pmcn), SiO2 (hexagonal, P3221), etc. The data of element and structure in Tibetan medicine Fanshi have been acquired by XRD, ICP-OES and XRD, and that is beneficial to exploring the material basis of Fanshi.