A multi-analytical approach for the characterization of powders from the Pompeii archaeological site

Abstract

Nine black powders found in Pompeii houses in three different types of bronze vessels (cylindrical theca atramentaria, unguentaries, and aryballoi) were characterized in order to assess a correspondence between the composition and the type of vessel and, possibly, to verify if these powders were inks or not. For the compositional characterization, a multi-analytical approach was adopted, which involved the use of scanning electron microscopy-energy dispersive X-ray, Fourier-transformed infrared spectroscopy, Raman, X-ray diffraction, electron paramagnetic resonance spectroscopy, thermogravimetric analysis, gas chromatography coupled with mass spectrometry (GC/MS), and pyrolysis GC/MS. Powders contained in cylindrical theca atramentaria form a homogeneous group, and their organic and inorganic compositions suggest that they were writing inks, while powders contained in unguentaries and aryballoi could have had several different uses, including writing inks and cosmetics. Furthermore, the composition profile of the powders found in cylindrical cases shows that, at 79 AD: , in Pompeii, carbon-based inks were still used for writing, and iron gall inks had not been introduced yet.

Revealing metallic ink in Herculaneum papyri

“…Both of these findings may have some effect on other archaeological studies. For instance, Canevali et al (23) analyzed black powders found in Pompeii's excavations to verify whether these powders were remainders of ink or make-up. Despite the presence of metals such as lead, they rejected different powders as candidates for writing inks primarily according to the archaeologists' assumption that at those times, in the Greco-Roman world, carbon-based inks without lead compounds were used exclusively.…”

Identifying and quantifying amorphous and crystalline content in complex powdered samples: application to archaeological carbon blacks

“…Five archaeological black powders were sampled from bronze and glass vessels found in houses in Pompeii (four in sector I and one in sector III; Table 1). The shape of the containers suggests the use as cosmetics (eye liner) for those found in balsamarium or unguentarium or as inks for those found in theca atramentaria (Canevali et al, 2011;Fig. S1).…”

Organic Residues in Archaeology: The Highs and Lows of Recent Research

“…Where inorganic colourants are also present, a combination of chromatographic and other techniques such as XRF, XRD, SEM, SEM-EDX, Raman and FT-IR can provide a complete characterization of the paints, dyes or other materials being analysed (28,122,(167)(168)(169). This approach has also proved successful in the analysis of vessel contents suspected of being paints, inks, medicines or cosmetics (168,170,171). For a round robin analysis of a 17 th century ointment, recreated to an authentic recipe, 11 laboratories used 10 different methods to analyse a sample of the ointment (172).…”