This article presents a study of five plaster samples coated with coloring material, which were unearthed in Iron I–IIA destruction layers at Rosh Pinna. The main aim of the examination was to determine the mineralogical composition of the plaster and to obtain information concerning technological aspects of how the plaster had been prepared. The petrographic examination of the plaster samples provides valuable information concerning the quality of materials and the technology used to coat the inner walls of Iron Age buildings.