Zhangpeishanite, BaFCl, occurs as minute inclusions in fluorite from the East Mine, Bayan Obo. It is tetragonal with s.g. P4/nmm, and lattice parameters, a = 4.3951(8), c =7.223(2) A, V =139.52(7) A, Z = 2. Zhangpeishanite is a member of the matlockite group (3DC.25), and is the Ba-dominant analogue of matlockite (PbFCl) and rorisite (CaFCl). The name is for Prof. Zhang Peishan (born 1925), a mineralogist, in recognition of his contributions to the mineralogy of Bayan Obo. The mineral and mineral name were approved by the IMA, CNMNC, #2006-045. The type material is deposited at the National Museum of Nature and Science (NSM-MF14696), and at the Institute of Geology and Geophysics, Chinese Academy of Sciences (KDX013).
