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The mining plant's wastes discharged in tailings ponds are under certain environmental conditions which cause chemical alteration, dispersion and mobility and therefore leading to a secondary mineralogy from the first one. In the district Zimapan, the orebody (skarn) containing Zn-Pb-Ag-(Cu) has generated a considerable amount of waste (50 years of disposal) stored in the ponds of San Miguel, Santa Maria and El Monte. The objective of this investigation was to determine the mineralogical neo-formation for the identification of the chemical behavior of metals in addition to environmental and health impact. An induction-coupled plasma spectrometry conducted revealed significant concentrations of trace elements in the chemical composition of the waste. The average concentrations were 13 135 mg/kg for As, 3 934 mg/kg for Pb, 11 363 mg/kg for mg/kg for Zn and 610 mg/kg for Cd. According to the mineralogical characterization using X-ray diffraction, calcite and quartz were identified as the majority mineral phases and gypsum, pyrite and sphalerite as the minority mineral phases as well as traces. During the completion of optical microscopy of polarization, sweeping electronics and electronic microsound, the neoformation of arseniates ferric (scorodite and symplesite), hydroxides and ferric sulfates and anglesite and cerusite was identified resulting from alteration, oxidation, sulphide hydrolysis such as arsenopyrite, pyrrhotite and galena. The sphalerite was classified as marmatite because of its iron content. As, Cd and Bi were found in particles of sulphosalts (boulangerite mineral); which can be released during meteorization; consequently, it was concluded that the waste is considered to be potentially toxic. [ABSTRACT FROM AUTHOR]