Nomenclature of the triphylite group of minerals

Abstract. In this paper we present a Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA-CNMNC)-accepted scheme for classification nomenclature triphylite group minerals. The general formula those minerals is M1M2TO4, where M1 M2 refer to cations in an octahedral coordination: = □, Na, Li; Mn2+, Fe2+, Mg, Fe3+, Mn3+, T tetrahedrally coordinated P5+ cations. contains Li-bearing phosphates [LiFe2+(PO4)] lithiophilite [LiMn2+(PO4)] their oxidation products heterosite [Fe3+(PO4)] purpurite [Mn3+(PO4)], as well Na-bearing natrophilite [NaMn2+(PO4)] karenwebberite [NaFe2+(PO4)]. Li–Mg-bearing phosphate simferite has been redefined LiMg(PO4). Ferrisicklerite sicklerite correspond intermediate phases triphylite–heterosite lithiophilite–purpurite solid solutions; consequently, according CNMNC dominant-constituent rule, they are discredited. A new mineral sequence defined, which considers different capacity iron manganese, therefore replaces traditional Quensel–Mason sequence. calculation procedure species, based electron microprobe analyses single-crystal X-ray diffraction data, also described.