Abstract In this study, volcanic ash from Ubinas and Sabancaya volcanoes in Peru were characterized by particle size, scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM/EDX), ICP MASS spectrometer, X-ray diffraction and specific gravity. The combined application of those techniques for the analysis provided complementary information, i.e., their elemental compositions and morphology. The results showed that the volcanic ashes (VA) have a particle size lower than 600 μm with a dominant size over 100 μm. Their mineralogical characteristics involve silica polymorphs, vitreous nature of silica and silicate particles, showing chemical heterogeneity within the micrometer sized particles and diverse morphology. The chemical composition of the ash is mainly SiO 2 , Al 2 O 3 , Na 2 O and CaO, with a high content of silica ranging from 57.78 to 66.14% and alumina ranges from 13.81 to 17.56%. The concentration of potential pollutant elements determined in products from Ubinas and Sabancaya volcanoes, namely As, Ba, Co, Cr, Cs, Fe, K, Mn, Mo, Sb, Sc, Sr, Th, Ti, U, V, and Zn, are reported. The different mineralogical characteristics among the studied volcanic samples would be related to their association with different volcanic eruptions. The chemical compositions and microstructure indicate that ashes have an origin and formation of andesitic and dacitic type.