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The northern slope of Mt. Vesuvius contains some interesting archaeological sites, including the site discovered in the town of Pollena Trocchia, where the remains, dated to between the 79 and 472 CE eruptions, document the transition from the Roman to late Roman cultural and socioeconomic settings. Profound changes occurred in this time interval, which can be inferred from changes in the ceramic manufacturing processes. Common wares, as the most widespread ceramic class in the archaeological record, are a useful example that illustrates this technological transformation. Seventeen samples of tableware, distinguished into three ceramic classes according to the method of slip application (i.e., Slipped Ware, Painted Ware "a straccio," and Painted Ware), were analyzed. The results highlight the use of high‐CaO clayey raw materials compositionally similar to Apennine clayey deposits. The clay bodies were occasionally tempered with sandy‐silt materials composed of volcanic grains with lesser amounts of siliciclastic fragments. Firing temperatures ranged from 800 to 950°C, as suggested by quantitative X‐ray powder diffraction and microstructural analyses combined with colorimetric measurements of the ceramic bodies. Micro‐Raman analyses performed on slips revealed the use of ochre for decorating the vessels; it was applied in a different way, representing an actual technological change. [ABSTRACT FROM AUTHOR]

In recent decades, μ-Raman spectroscopy has become a powerful technique for studying ceramics, with the advantage of performing fast, reproducible and reliable analyses that provide effective information on ceramic technology. In the present paper, the potential of μ-Raman spectroscopy was evaluated by comparing the results of spectroscopic analyses with a wide range of conventional compositional and mineralogical analyses. Particular fragments of pottery from the archaeological site of Pollena Trocchia (Campania, Italy), characterized by a variegated color zonation, a symptom of uncontrolled firing conditions, were subjected to in-depth analytical investigation. Data from the μ-Raman measurements were in very good agreement with the analytical set of conventional analyses and permitted to better constrain the firing temperatures, evaluate changes in the oxidative steps, and assert the provenance of volcanic raw materials. The results illuminated that pottery was crafted by mixing a low-CaO base clay with volcanic temper from the environs of Vesuvius and fired in a not well-controlled firing atmosphere, which determined the development of Fe(III) oxides at rims of sherds and Fe(II)-bearing phases at cores. Moreover, even in the absence of newly-formed minerals, firing temperatures were estimated between 900 and 950 °C, as suggested by the mineralogical and spectroscopic evidence of the prograde 10 Å dehydroxylated phyllosilicates. • The technology of ancient ceramics was investigated by μ-Raman spectroscopy (μ-RS). • A methodological approach comparing data from μ-RS and traditional analytical routine was used. • Ceramic samples are featured by a color zoning as a symptom of uncontrolled firing condition. • The comparative approach highlighted the affordability of μ-RS to reconstruct the ceramic process. • Firing conditions were constrained by analyzing the spectral features of ceramic matrix. [ABSTRACT FROM AUTHOR]