A Note on a Modern Lead White, also Known as 'Synthetic Plumbonacrite'

Abstract

This article reviews conflicting information found in the literature about the composition and structure of a type of lead white developed in the first half of the twentieth century: pentalead tricarbonate dihydroxide oxide, 3PbCO3·Pb(OH)2·PbO, also known as synthetic plumbonacrite, a pigment that has been described as being 'pearlescent' or 'nacreous'. X-ray diffraction allows pentalead tricarbonate dihydroxide oxide to be distinguished from the more common form of lead white, trilead dicarbonate dihydroxide, 2PbCO3·Pb(OH)2. X-ray diffraction data for the two compounds are given, as well as for lead carbonate, PbCO3, which is often associated with trilead dicarbonate dihydroxide. Experimental data are presented for several paint samples in which pentalead tricarbonate dihydroxide oxide was found. These samples were also characterized by polarized light microscopy and scanning electron microscopy. Although some samples were found to be pearlescent or nacreous in appearance, others were not.