Glazes and Enamels

Raman identification of the different glazing technologies of Blue-and-White Ming porcelains

“…3 (spectra also recorded with 785 nm excitation), to the asymmetric stretching vibration of SiO 4 tetrahedra although only the symmetrical stretching modes contribute significantly to Raman scattering and these are located between ~850 and 1100 cm -1 according the degree of polymerization of the silicate matrix. [36][37][38] Obviously, more analyses are needed to document better the differentiation between the final products of the glazing procedure, namely single or multiple steps, especially using non-invasive spectroscopic techniques.…”

“…Nevertheless, the calculation of the polymerisation indices directly linked to the melting temperature of the vitreous silicates 21,[36][37][38] shows that the two types of enamels (alkaline or rich in calcium) have been fired at different temperatures The double glazing technique could explain why Kraak wares 47,48 from shipwrecks maintain their high gloss although other porcelain samples become pitted and glossfree.…”

Non-Invasive On-Site pXRF Analysis of Coloring Agents, Marks and Enamels of Qing Imperial and Non-Imperial Porcelain

“…The techniques for coloring a layer of glass implement with three types of coloring agents: (i) Ions exhibiting absorption in the visible, i.e., having an incomplete 3d electronic shell (transition metals) or 4f (rare earths) dissolved in the silicate network; (ii) nanoparticles absorbing in the visible, i.e., low-band gap (metals such as gold, copper or silver and semiconductors such as CdS and CdSe); (iii) pigments colored by the means mentioned above, prepared separately and dispersed in the silicate powder before firing or forming on cooling from the silicate melt oversaturated in certain elements [1][2][3][4]. The technical literature shows that, for the same visual aspect, several preparation techniques are possible [1][2][3][4][5][6].…”

“…The techniques for coloring a layer of glass implement with three types of coloring agents: (i) Ions exhibiting absorption in the visible, i.e., having an incomplete 3d electronic shell (transition metals) or 4f (rare earths) dissolved in the silicate network; (ii) nanoparticles absorbing in the visible, i.e., low-band gap (metals such as gold, copper or silver and semiconductors such as CdS and CdSe); (iii) pigments colored by the means mentioned above, prepared separately and dispersed in the silicate powder before firing or forming on cooling from the silicate melt oversaturated in certain elements [1][2][3][4]. The technical literature shows that, for the same visual aspect, several preparation techniques are possible [1][2][3][4][5][6]. For a long time, most of the colored glazes and enamels were prepared from two mixtures: One enriched in coloring agent(s) (e.g., smalt, the cobalt-rich potash glass that contain up to ~20 wt% CoO [6]), called anima in ancient recipes [7] and a colorless mixture (corpo) that will form the silicate matrix [1,8], convenient for the control of the melting temperature, the thermal expansion and the viscosity, etc.…”

Microstructural characterization of ceramic artifacts made using the raku technique

“…Some artifacts can be seen in Figure 1. (Huang & Hsiao, 2019;Philippe Colomban, 2020). The Adamas atelier, inaugurated in 2004, is among the group that practices this technique, and it will serve as the object of study for this paper.…”