Mineralogical and geochemical characterization of archaeological ceramics from the 16th century El Badi Palace, Morocco

Abstract

Textural, mineralogical and chemical characterization of archaeological ceramics (zellige) from El Badi Palace (Marrakech, Morocco), the main Islamic monument from the Saadian period (sixteenth century), has been performed to enhance restoration and to determine the technology of manufacturing. A multi-analytical approach based on optical and scanning electron microscopy, cathodoluminescence, X-ray fluorescence and X-ray diffraction was used. Re-firing tests on ceramic supports were also performed to determine the firing temperatures used by the Saadian artisans. A calcareous clay raw material was used to manufacture these decorative ceramics. The sherds were fired at a maximum temperature of 800°C in oxidizing atmosphere. The low firing temperature for ‘zellige’ facilitates cutting of the pieces, but also causes fragility in these materials due to the absence of vitreous phases.

Non-destructive determination of the biotite crystal chemistry using Raman spectroscopy: how far we can go?

“…Phyllosilicates can be found in a variety of cultural-heritage objects such as clay tablets (e.g., Uchida et al, 2015), seals (Zazoff, 1983), earth pigments (e.g., Hradil et al, 2011;Corradini et al, 2021), blotting sand (e.g., Milke, 2012), archeological decoration-related ceramics (e.g., Bersani and Lottici, 2016;El Halim et al, 2018), inscribed gems (e.g., Wang et al, 2013;Bersani and Lottici, 2016;Mihailova et al, 2021, and references therein), and in general as weathering prod-ucts on the surface of common rock-forming silicate minerals (e.g., Velbel, 1993). To achieve a detailed insight into the locality and provenance of such cultural-heritage objects (e.g., Bersani and Lottici, 2016;Mihailova et al, 2021), the determination of the mineral/phase composition as well as of the crystal chemistry within each single mineral constituent is necessary.…”

Archaeometric Investigations on Archaeological Findings from Palazzo Corsini Alla Lungara (Rome)

“…The presence of iron oxides in all of the ceramic fragments indicates that they were fired in an oxidising environment [37,38].…”

Non-destructive portable X-ray Fluorescence (pXRF) method for the characterization of Islamic architectural ceramic: Example of Saadian tombs and El Badi palace ceramics (Marrakech, Morocco)

“…5D). In the Saadian Zellige of El Badi Palace, the analysis of blue glazes using a Panalytical Axios XRF spectrometer shows that phosphorus is the main agent responsible for this color with a content around 7.5 wt% (El Halim et al, 2018). The contents of silica and lead in these samples range respectively from 42.8 wt% to 62.6 wt % and 25.5 wt% to 50.2 wt%.…”

“…Previous studies show that the white glaze in the Saadian monuments (e.g. El Badi Palace) is obtained by cassiterite (SnO 2 ) mixed with lead and silica (Gradmann et al, 2015;El Halim et al, 2018), but tin oxide cannot be detected by the Bruker AXS handheld analyzer instrument used (device detection limit). CaO can be used as whitening agents like SnO 2 but the higher lime contents observed in some white, black, yellow and green glazes (> 5 wt% of CaO) could also be due to efflorescence of the surface when the shard was made from calcareous clays (Walton and Tite, 2010).…”

“…The need for having valid and useful heritage documentation is therefore evident and should constitute a priority action in any type of restoration (Almagro, 2013). Unfortunately, in these studied monuments, the availability of proper documentation is very limited (Gradmann et al, 2015;El Halim et al, 2018), as is the case in most historical monuments of emerging or developing countries in the South and East Mediterranean areas. To this end, the aim of this study is to characterize the chemical composition of the different glazes ceramics and to emphasize their evolution over time.…”