Arianna's Palette: A Diagnostic Study of the Painting Walls of the Domus of Arianna in Pompeii

The House of Arianna, also known as the House of Colored Capitals, represents, with its 1700 m2 of floor space, one of the most majestic examples of a residence within the Pompeii archaeological site. The research developed within the project “Cultural Heritage Active Innovation for Sustainable Society—CHANGES” reports the outcomes of the archaeometric study of polychrome wall paintings that decorate Room Number 6 of the Domus of Arianna. To achieve this goal, noninvasive on-site techniques were employed, along with three-dimensional digitization procedures for mapping diagnostic analyses on numerical models of the painting walls and the geometric survey of spaces. The results show that different colors were obtained by using pure, natural, and synthetic pigments including calcite, red and yellow ochre, red lead, cinnabar, green earth, Egyptian blue, and carbon black. These pigments were also combined to obtain specific shades, such as for green and pink shades. Lastly, signals of incipient alteration have been highlighted by spectroscopic analyses Raman and FTIR.