Spectroscopic investigation of yellow majolica glazes

Abstract

The yellow decorations of some ceramic art objects were examined through different spectroscopic techniques and optical and electronic microscopy. The yellow pigment was identified as lead antimonate, the well-known Naples Yellow. Its use in the course of history seems to be strongly discontinuous, but the diagnostic techniques used to date may not have been adequate. Samples from original masterpieces have been compared with a yellow pigment synthesized in our laboratory, following a Renaissance ancient recipe for Naples Yellow. Concordant results were obtained with Fourier transform IR and UV-visible reflectance spectroscopy, Raman microscopy, optical microscopy and scanning electron microscopy. It is demonstrated that the micro-Raman technique is very effective for the unambiguous identification of the pigment and its firing temperature.

X-ray fluorescence (conventional and 3D) and scanning electron microscopy for the investigation of Portuguese polychrome glazed ceramics: Advances in the knowledge of the manufacturing techniques

“…The crystals identified in both images (a and b) have a triangular and hexagonal shape, which is typical for the Naples yellow pigment [12,14]. Additionally, the shape of the crystals is also a hint to estimate the firing temperature.…”

“…Due to the lack of archaeometric information on Portuguese ceramic production, we used the knowledge from previous works performed on Spanish and Italian glazed ceramics [4,8,10,[12][13][14], since we are dealing with similar types of samples. Hence, this work presents the first archaeometric results about Portuguese glazed ceramics produced in Coimbra and Lisbon as a comparative study.…”

“…From the spectra, we see that this pigment comes from the same compound, which is a lead-antimony (Pb 2 Sb 2 O 7 ) composite called Naples yellow [12]. In fig.11c, we can see that the samples from Coimbra appear to have higher Fe and Mn count rate than the ones from Lisbon.…”

“…Additionally, the shape of the crystals is also a hint to estimate the firing temperature. According to [12], from 950 ºC…”

Lacquerware Pigment Identification with Fixed and Mobile Raman Microspectrometers: A Potential Technique to Differentiate Original/Fake Artworks

“…Pigments and specific mixtures by which sometimes they were commercialized can be used to trace given periods of production. Therefore identification of specific pigments in artwork can be used for dating purposes, as was already demonstrated for paintings, glass, ceramic or enameled metal objects [1,3,[5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Their presence of certain pigments may indicate a restoration, later embellishment or identify a fake or a modern replica.…”