La fosfosiderite della Malpensata: prima segnalazione a Piona, Lecco

Spherical aggregates of microcrystals filling hydrothermal cavities or earthy masses with pale lavender color of probable phosphosiderite were found by one of the authors (F.V.) in the dumps of the Malpensata pegmatite mine. This hydrated Fe phosphate had been identified by means of electron microprobe in wavelength dispersive mode (WDS) and powder Xray diffraction analysis (XRPD). Chemical analyses (Table 1) revealed the following empirical formula (Fe1,02Mn0,02)?1,04(PO4)?2,08H2O, and the XRPD analysis gave the following unitcell parameters a = 5,301(4) Å, b =analysis gave the following unitcell parameters a = 5,301(4) Å, b = 9,778(6) Å, c = 8,726(4) Å e ? = 90,3(1) ° in close agreement with those reported for this mineral species.