Litharge obtaining from the roasting of lead white. Chromatic characterization of obtained products

The yellow lead known as litharge (alpha-PbO) is usually classified within the group of yellow pigments. Nevertheless, there is not an agreement in the literature about its chromatic description. This discrepancy in its description leads to the hypothesis of a possible heterogeneity in its composition derived from its manufacturing process. Its production in a laboratory from roasting of the lead white (at 330 degrees.C) and its variation with time (from 15 min. until 12h) has allowed the study of the chromatic characteristics of the formed compounds. It has also been possible to verify that the litharge formation is accompanied of other lead oxides (massicot and minium), as well as carbonates lead oxides. The nature and proportion of these compounds determine the chromatic values of the pigment.