© 2019, Universidade Federal do Rio de Janeiro. All rights reserved. Despite the exceptional architecture and polychromy of archaeological site of Tambo Colorado, there has been no conservation work or in the architectural structures of raw earth, nor on the surfaces. These jobs re-quire a proper understanding of the state of conservation of the site architecture and the analysis of the mate-rials used. With this purpose, the results of the present study tries to explain the nature of the materials (pig-ments) used in the mural paintings, as well as determine the sources of these materials (quarries). To do this, pigments of quarry were investigated by the technique of X-ray diffraction, using synchrotron radiation, and structural refinement by the Rietveld method. It was determined the composition of pigments, identifying the phases of anorthite, quartz, hematite, chlorite, halite, gypsum, orthoclase, illite, jarosite, calcite, kaolinite, zinwaldite, cristobalite, anhydrite and albite. Rietveld refinement confirmed the presence of these phases and determined the percentage by weight of each of them.