View article

The Sapucaia pegmatite is located in the well-known Eastern Brazilian Pegmatitic Province (EBPP), Minas Gerais, Brazil. Detailed mapping of the pegmatite body revealed five zones, showing distinct mineral assemblages: a border zone (BZ), an external wall-zone (EWZ), an internal wall-zone (IWZ), an intermediate zone (IZ), and a quartz core (Q). Phosphate masses found in the pegmatite contains two different assemblages: assemblage I is formed under oxidizing conditions, and assemblage II is formed under less strongly oxidizing conditions. In both assemblages, triphylite is the only primary phosphate, and several secondary species are produced by its alteration. In association I, three main transformation stages are observed:(i) the progressive oxidation of triphylite accompanied by the leaching of Li leads to the successive crystallization of ferrisicklerite and heterosite;(ii) a hydration stage transforms triphylite …