Comparative analysis of wucai Chinese porcelains using mobile and fixed Raman microspectrometers

Abstract

International audienceThree porcelain shards representative of wucai (Famille verte, Famille rose and fencai), enamelled wares from Kangxi, Yongzheng and Qianlong reigns have been studied using fixed instruments (optical microscope, EDS-SEM and Raman microspectrometer) in order to identify the amorphous and crystalline phases in the glaze, body and the different enamels. A comparison is made between the information collected with portable Raman setups excited with 532 and 785 nm lasers and equipped of sophisticated optics. Emphasis is put on the detection of pigments and opacifiers, in particular arsenic-based phases in blue coloured areas, in relation with the use of cobalt ores originated from European or China. The mobile Raman setup excited with green laser and equipped with a high magnification (x200) ultra long working distance microscope objective allows the identification of all the phases, as for the fixed instrument excited with blue 457 nm laser line. Confirmation of the identified phases is made by SEM-EDS. The old technologies are discussed and compared to those used to produce 18 th century French soft paste porcelains and Limoges enamels

On‐site Raman study of artwork: Procedure and illustrative examples

“…On‐site analyses of very rare huafalang items—which, based on the style, seem to have been fired at the Imperial Court Workshop during the end of the Kangxi reign (~1715–1722)—identify lead arsenate in blue décor. The identification of lead arsenate in blue enamel only demonstrates the use of European cobalt ore, a proposal confirmed by elemental composition analysis of some wucai shards . Rather, similar bowls produced at the same workshop and period show different features, thus demonstrating a period of intense innovation.…”

“…The identification of lead arsenate in blue enamel only demonstrates the use of European cobalt ore, a proposal confirmed by elemental composition analysis of some wucai shards. [99][100][101] Rather, similar bowls produced at the same workshop and period show different features, thus demonstrating a period of intense innovation. Lead can be partially substituted by potassium or calcium, giving complex solid solutions and some variety in the Raman signature.…”

“…Gemstones [30,33,37,40,41,126,127] Pigments of illuminated manuscripts [48,128,129] Wall paintings and frescoes [130,[132][133][134][135][136]144] Rock art [137][138][139][140][141] Buildings and stones [117][118][119]142,143] Glass, glaze, and pottery [31,32,43,[49][50][51][52][53][54]91,92,101,[103][104][105][106] Bronze corrosion and patina [123] Iron/steel corrosion layer and patina [114,116,117] Paintings pigments [13,125,…”

The Raman signature of protonic species as a potential tool for dating or authentication of glazed pottery

“…Figure S3 shows the as‐recorded and wave‐corrected Raman spectra of the Qing Famille Rose porcelain sample (Q‐r) obtained from preliminary measurements performed on the section of shards at different distances from the glaze surface in the high wavenumber region . Unfortunately, in this preliminary work, the selected wavenumber window (3,000–3,800 cm −1 ) being too small hinders the clear observation of all the components.…”

“…painted decorations. Their detailed descriptions can be found in a very recent study . The last Chinese porcelain sample is a modern fake of the Ming Dynasty blue‐and‐white.…”