Application of WDXRF in the provenance studies of Persian haft rang tiles: a statistical approach

Abstract

An outstanding style of Persian tilework, which emerged from the north‐eastern Iran in the 15th century, was extensively used for decorating architectural facades during the Safavid period (from the 16th through the 18th century). This type of tilework, the so‐called haft rang, technically comprises of forming a clay body and firing two glazed layers on top of the body. In the present paper, the first analytical data concerning haft rang tiles is provided. To do so, forty three samples of Safavid haft rang bodies were analysed by wavelength dispersive x‐ray fluorescence (WDXRF) and the obtained data were handled by principal component analysis (PCA). The results showed that the 17th century haft rang tiles wherever found are local products; that is, Safavid tile‐makers have used local clay sources to make the bodies of haft rang tiles. The analytical data also showed that old tileworks, in general sense, can be simply replaced by newly manufactured tiles or, at least, all tilework revetments in an individual edifice might not have been produced in an identical workshop. Moreover, WDXRF was used as an accurate and precise method to determine the chemical composition and to support compositional classification in provenance studies and can be considered as a reliable alternative for studying the provenance of archaeological ceramics. Copyright © 2013 John Wiley & Sons, Ltd.

A new look at XRD patterns of archaeological ceramic bodies

“…All the aforementioned remarks regarding anorthite and wollastonite may convey that the fourth group's bodies have been fired at temperatures from 950°C to 1,000°C (Table 1). However, one should consider that anorthite could be originally present in the composition of some bodies as Q.J.1, Q.J.2 and Q.J.3 bodies did show plagioclases in their bodies introduced from volcanic tuffs originally present in the clays of the bodies [54] (Fig. 1b).…”

“…So that, the first letter in the samples' labels is referring to the city, the second letter to the site of sampling and the numerical part of the labels shows how many samples were collected from each site (Table 1). Chemical composition, provenance and visual characteristics of the samples are provided by Holakooei et al [53,54]. In order to offer a general idea about the texture of the samples, the cross sections of three representative fragmentary tiles are demonstrated in Fig.…”

“…Cutting Since any reliable discrimination between the gehlenite and åkermanite by XRD patterns is not generally easy and possible [79], we used gehlenite to cover the term åkermanite as well b WDXRF data are already presented by Holakooei et al [54] c Due to the high amorphous and firing minerals (anorthite, wollastonite, and gehlenite) content, the calcite content has most probably a secondary origin samples were carried out with a particular care to remove the contaminated parts which were in contact with masonry used for adhering haft rang tiles on walls. XRD patterns of about 100 mg of the powdered samples were acquired using a Philips PW 1830 generator with a PW 1820 goniometer working with Cu-Kα radiation (λ = 1.5406 Å ), at 40 kV and 30 mA, and a step size of 1°/2θ/min in the 4-73°2θ range.…”

Cluster analysis of XRPD data in ancient ceramics: What for?

“…Unlike chemical data, on which multivariate statistical tools have long been applied in studying ancient pottery (methodological papers: Mommsen et al, 1988;Tangri and Wright, 1993;Baxter, 1994Baxter, , 1999Baxter, , 2006Baxter, , 2008Neff, 1994;Buxeda i Garrigós J., 1999;Baxter and Buck, 2000; some case studies: Maritan, 2004;Maritan et al, 2013;Holakooei et al, 2013;Baklouti et al, 2015), cluster analysis has only recently been applied to XRPD data in archaeometry, to study the production recipes of ancient mortars (Piovesan et al, 2013) and in the geological field, for grade control of iron ores (Paine et al, 2012); principal component analysis has been performed on Iranian tiles (Holakooei et al, 2014). The great potential of cluster analysis of XRPD data is that it can compare the similarity of the whole dataset, through the "figure of merit", which quantifies matching among scans and does not require a priori quantification of the phases composing each sample.…”

Combination of wavelength dispersive X-ray fluorescence analysis and multivariate statistic for alluvial soils classification: a case study from the Padanian Plain (Northern Italy)

“…[1] In particular, XRF spectrometry is an accurate, precise, fast and reliable method to determine the bulk elemental soil composition for environmental screening. [2] Soil chemical composition may vary widely because of variations in soil mineralogy and texture.…”