The enamels of the first (soft‐paste) European blue‐and‐white porcelains: Rouen, Saint‐Cloud and Paris factories: Complementarity of Raman and X‐ray fluorescence analyses with mobile instruments to identify the cobalt ore

International audienceThe first porcelains made in Europe during the 17 th century and the very beginning of the 18 th century, i.e. before the discovery of kaolin in Saxony (Germany), are rare and technical analyses very limited. In contrast with Meissen Böttger porcelain based on kaolin, these porcelains are made with sand and 'chymie', like Ottoman fritware. A selection of the blue-and-white artefacts belonging to the French national collection is analyzed on-site with mobile pXRF and Raman setups: two were assigned to the Poterat Factory at Rouen, three to the Saint-Cloud Factory and two to the Pavie Factory (Paris). Three types of enamels are identified, lead-rich (as expected) but also two different lead-alkaline-earth-alkali enamels, one artefact being covered both with lead-rich and lead-poor enamel. The polymerisation index deduced from the relative intensity of SiO 4 bending and stretching bands indicates different temperatures of firing. Tin is detected in most of the enamels by XRF but cassiterite opacification is only observed for the Pavie factory artefacts. Arsenic is detected in the blue areas due to the use of European cobalt ores. Comparison of trace and minor elements as well as the type of enamel used suggest that the pot assigned to the Rouen factory fits much better with a production from the Saint-Cloud factory. The two porcelains assigned to the Pavie factory exhibit similar XRF and Raman signatures that support the attribution based on visual criteria. Combination of the mobile non-invasive XRF and Raman instruments may allow the reliable classification of artefacts on-site. Raman scattering is very efficient to detect (on-site) As-based minor phases