Discovery and characterization of a struvite layer in the Chalco paleolake, Mexico

  • Teresa Pi
  • Socorro Lozano-García
  • Margarita Caballero-Miranda
  • Beatriz Ortega-Guerrero
  • Priyadarsi Roy
Keywords: phosphate, X-ray diffraction, infrared spectra, thermogravimetric analysis, Rietveld refinement


Centimeter-sized crystals of struvite (MgNH4PO4·6H2O) were found during the drilling of a core from Chalco paleolake, Mexico for paleoecological and paleoclimatical research. Struvite is a biogenic mineral, unstable in most geological environments. The unusual size and preservation of these struvite crystals allowed us to perform a chemical and mineralogical characterization. This is the first record of struvite from a geological locality in Mexico, and one of the most remarkable in the world.