Backscattered electron and major element maps of pumice from the 1991 eruption of Mount Pinatubo, Philippines. Samples provided by Mauro Rosi; for detailed description of location and eruptive stratigraphy see the following paper: Rosi, M., Paladio-Melosantos, M., Di Muro, A., Leoni, R. and Bacolcol, T., 2001. Fall vs flow activity during the 1991 climactic eruption of Pinatubo Volcano (Philippines). Bulletin of Volcanology, 62, pp.549-566. Backscattered electron maps were obtained on a Zeiss Sigma HD Field Emission Gun analytical scanning electron microscope (ASEM). Major element maps were obtained on the same ASEM using dual Oxford Instruments X-max 150 mm2 energy dispersive silicon drift detectors.