Non-Invasive on-site Raman study of blue-decorated early soft-paste porcelain: the use of Arsenic-rich (European) cobalt ores-Comparison with huafalang Chinese porcelains

Philippe Colomban (1) , Ting-An Lu (1) , Véronique Milande (2)

1 MONARIS - De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies
2 Cité de la céramique

A Raman study of a Sèvres soft paste (frit) porcelain plate allowed the identification of both the crystalline and amorphous phases. Cristobalite and pseudowollastonite gave main Raman signatures in the body where also tridymite, amorphous alkali silicate glass and lead arsenate apatite were detected. Na0.4K0.1Ca0.5Pb4(AsO4)3 lacunar apatite is identified as opacifier in blue and green overglaze enamel. Pb-Sb-reach pyrochlore (Naples Yellow) pigment was found in yellow and green overglaze enamels. The orange hue is obtained by superposing a hematite bearing red paint stroke over the yellow. These results are compared to those previously obtained by detailed OM, SEM, XRD and XRF analyses. Some of the phases identified by XRD (quartz, tridymite) are hardly detected by Raman and vice versa cristobalite was not found by XRD, most probably due to its low amount.

Mots clés: Porcelain; Enamel; Fritware; As-Pb apatite; Blue

Domaines: Matériaux

Philippe Colomban, Ting-An Lu, Véronique Milande. Non-Invasive on-site Raman study of blue-decorated early soft-paste porcelain: the use of Arsenic-rich (European) cobalt ores-Comparison with huafalang Chinese porcelains. Journal of the European Ceramic Society, 2018, 38 (15), pp.5228-5233. ⟨10.1016/j.jeurceramsoc.2018.07.001⟩. ⟨hal-01900407⟩