The composition, structure, thermal stability and trace elements of the unprepared and calcined pyrite (Zirantong) samples from different places, used as traditional Chinese medicine, were determined and calculated by using XRD, TG-DTA and ICP. The results indicated that in the unprepared pyrite, the phase is mainly made up of FeS2, but in the calcined pyrite, the phase varies with the origin of the medicine, such as FeS2 (86% from Nanjing University of Traditional Chinese Medicine, 89% from Hunan, 32% from Sichuan, 19% from Shanxi), FeS (11% from Hunan, 24% from Anhui, 24% from Sichuan), Fe3O4 (29% from Anhui), Fe2O3 (14% from Anhui), FeO(OH) (14% from Nanjing University of Traditional Chinese Medicine, 74% from Shanxi) and so on. When heated from 450 to 800 ℃, the phase FeS2 can be gradually changed into FeS. In these mineral medicines there are a plenty of trace elements correlative with health of the human body, which are not only some beneficial trace elements, such as Ca, Fe, Zn, etc, but also some harmful trace elements, such as As, Cd, Pb, etc. The results may provide basis for quality evaluation of the medicine.

Key words: mineral traditional Chinese medicine, pyrite (Zirantong), X-ray powder diffraction, thermal analysis, trace element