Brightly Colored to Stay in the Dark. Revealing of the Polychromy of the Lot Sarcophagus in the Catacomb of San Sebastiano in Rome

Abstract

The Lot Sarcophagus is one of the most relevant funerary sculptures of late antiquity (mid-4th century AC). Some of the remarkable aspects are the following (i) it is still preserved in situ; (ii) most of the carved scenes are rarities or unicum; (iii) not all the sculpture work has been completed, which allows us to analyse the executive process; (iv) many traces of polychromy have remained. This paper is focused on the characterization of the residual polychromy by using in-situ non-invasive techniques. Furthermore, few micro samples were taken, to be analysed in laboratory to study the composition of some deposits and to define if a preparatory layer was present under the coloured layer. The data showed that the very rich polychromy of the Lot Sarcophagus was made of Egyptian blue, yellow ochre, and three different types of red: two inorganics (red ochre and cinnabar), and one organic-based (madder lake). Furthermore, some decorations, completely vanished and no longer visible to the naked eye, have been rediscovered, also providing details on the construction phases. During the project, the 3D model of the sarcophagus was acquired, which afterwards was used to map the results of the diagnostic campaign.

pXRF and Polychromy: Identifying Pigments on Limestone Statuary from the Roman Limes, Preliminary Results

“…The black was identified as hydroxyapatite (Ca 5 (PO 4 ) 3 (OH)-bone black, previously considered less common than carbon-based blacks. However, emerging heritage materials science techniques have detected bone black in pigment mixtures on wall paintings, sarcophagi, and stele from Antiquity [45][46][47][48]. The previous SEM/XRD report suggested the green to be "Egyptian green" based on the presence of cuprorivaite, but it is herein confirmed as Egyptian blue (CaCuSi 4 O 10 ), a calcium-copper-silicate with a crystalline structure in use since the 3rd Millennium BCE in Egypt.…”

New frontiers review of some recent conservation techniques of organic and inorganic archaeological artefacts against microbial deterioration

“…In order to preserve our cultural heritage for future generations, interdisciplinary research teams embraced by microbiologists, geologists, chemists, physicians, archeologists, and ecologists should be involved in the challenging research opportunities of heritage conservation science. The mechanisms of biodeterioration by microbial communities lead to the right choice of efficient conservation technique (Bracci et al, 2020).…”

Unveiling the paint stratigraphy and technique of Roman African polychrome statues

“…Lastly, systematic studies have been conducted on the remains of paint on marble sculptures, but few analytical publications contain a description of the analytical methodology (Brons et al 2020;Magrini et al 2019;Bracci et al 2020;Alfeld et al 2017;Aggelakopoulou and Bakolas 2022;Abbe and Şare Ağtürk 2019). The commonly defined noninvasive standard protocol involves the use of multispectral imaging and video microscopy coupled with non-invasive punctual spectroscopies (Raman, XRF, FTIR) corresponding to the areas where the remains of colour are observed (Østergaard 2018).…”