Technological study of the seventeenth century haft rang tiles in Iran with a comparative view to the cuerda seca tiles in Spain

The history of polychrome glazed objects in Iran is synchronised with the history of the first known examples of polychrome glazed artifacts. The polychrome glazed bricks of Chughā Zanbīl, dated back to the thirteenth century BC, might be the first evidences of such a claim. This tradition was followed until the fall of the Achaemenids in the fourth century BC, when glazed bricks objects were vastly used to cover the friezes of palaces and important edifices at Persepolis and Susa. Making polychrome glazes on ceramic materials, however, seems to be abandoned until the Islamic period, when polychrome underglaze objects were widely in use in Iran from the tenth century onwards. The first evidences of creating overglaze polychrome decoration was nevertheless achieved on mīnā�ī glazed objects in the thirteenth century AD, which as Abu’l Qasim stated used be originally called haft rang, e.g. ‘seven colours.’ This technique was slightly modified and used throughout the fifteenth and sixteen centuries in Iran, and then was extensively used in the seventeenth century over the Safavid period (1501-1736). In all these types of polychromies, a dark colour line (mostly black) is used to separate various coloured glazes. This technique is still alive and is widely used in decorating the architectural facades of scholastic buildings in Iran. In the twentieth century, art historians attributed this type of polychrome technique to a Spanish style of making polychrome glazed objects called cuerda seca. The only feature by which such an attribution is established is a ‘black line,’ which is used in both techniques of haft rang and cuerda seca for separating coloured glazes. This thesis provides firsthand information about the seventeenth century haft rang tiles in Iran using various analytical approaches, including optical microscopy, wavelength dispersive x-ray fluorescence (WDXRF), x-ray diffraction (XRD), densitometry, ultraviolet visible spectroscopy (UV-Vis spectroscopy), micro-Raman spectroscopy, and energy dispersive x-ray spectroscopy (EDS). Here, optical microscopy was mainly used to have a general idea about the stratigraphy and various layers of the haft rang tiles. WDXRF was however used to respond to the question of the provenance of the tiles as this subject has always been of interest to frame the archaeological context of haft rang tiles. Another issue emphasised in this thesis is the thermal history of the tiles, which was studied by XRD and measuring the density of the bodies’ tiles. This subject was particularly was interesting for me to delve into because multi layer structure of haft rang tiles makes the study of thermal behaviour of the bodies much complicated. On the other hand, the study of the coloured glazes was firstly achieved by UV-Vis spectroscopy, where the possible colourants and network modifiers of the glazes were studied. Micro- Raman spectroscopy, however, presented very notable results about the opacifiers and un-dissolved particles suspended in the glazes’ matrixes. EDS microanalyses were nonetheless carried out to have a general idea about the chemical composition of the glazes and their fluxes, opacifiers, and network formers. ii The results of the aforementioned studies showed that, regardless where they are found, the bodies of the seventeenth century haft rang tiles are local products and are not imported from other centres of tilemaking. Moreover, under the optical microscope three layers of a terracotta body, a white glaze, and coloured glazes could be observed in a single haft rang tile from the bottom up to the top of the tile. In addition, the thermal history of the tiles’ bodies showed that the tiles were not fired most probably at temperatures higher than 1000°C. In fact, the equivalent firing temperature (EFT) of the majority of these tiles was estimated to be between 800 and 1000°C. As far as the white glaze is concerned, it was achieved by dispersing tin oxide particle in an alkali glaze as opacifier. The lead content of the white glazes can be technically associated with the manufacturing white glazes in medieval Iran, where tin and lead was roasted to make an opacifier for alkali glazes. Another issue concerning the white glaze was its maturing temperature, which was estimated to be at about 850°C. The yellow glazes were however achieved by dispersing lead tin yellow particles in a lead-based glaze. The green and brown glazes were practically the yellow glazes in which copper(II) and iron(III) respectively used. The maturing temperature of the yellow, green, and brown glazes was calculated to be roughly placed at 615°C. The blue, violet, and turquoise glazes showed however different behaviour by an alkali matrix in which cobalt(II), manganese(III), and copper(II) had yielded the blue, violet, and turquoise tones. The maturing temperature of these glazes was assessed to be at about 700°C. The black lines did not show to be true glazes due to the high alumina and manganese oxide contents in their composition. The high maturing temperature of about 1150°C of the black glazes revealed very interesting results. This property has certainly been of interest in manufacturing haft rang tiles; that is, when the low temperature glazes were runny enough to be mixed together, the black line was resistant enough to keep separated the glazes in order not to run together. The relatively higher maturing temperature of the white glaze has also been desirable since it does not softened in low temperatures at which the upper coloured glazes were runny and the chance of mixing the white glaze and the upper glazes was substantially lessened. Another subject on which this thesis shed light is the attribution of haft rang technique to the Spanish technique of cuerda seca. In the discussion and final chapters of the thesis, an attempt is made to put together the technological features of these two techniques. What can be at least understood on the evidences exist about these two techniques is that there is no technological reason by which haft rang technique can be attributed to cuerda seca. The use of black line for separating coloured glazes in Iran, as showed in this thesis, has a history much longer the history of cuerda seca. Hence, I have finally suggested that cuerda seca is an inappropriate term to cover the seventeenth century Persian polychrome tiles. The term ‘haft rang,’ which is used for nominating the antecedents of the seventeenth century polychrome tiles, is preferred in this thesis as this term is also widely used in today’s Iran to address this type of polychrome tiles. Parviz Holakooei Ferrara, Italy March 201

a technological study on the 17th century raised gilded substrates in three royal palaces of isfahan iran

The raised substrates of gilding decorations, called lāyachīnīī in Persian, were widely used throughout the Safavid period (1501-1736 AD) in Iran. This paper presents the first analytical data obtained from the lāyachīnīs of three seventeenth century royal Safavid buildings (ʿAlī- Qāpū, Chihil-Sutūn, and Hasht-Bihisht) in Isfahan, Iran, using energy dispersive X-ray spectroscopy, scanning electron microscope, Xray powder diffraction, and thin layer chromatography. According to the analytical data, different forms of calcium sulfate (dihydrate, β-hemihydrate, and anhydrite), the red iron oxides, and a proteinaceous binder (probably animal glue) are the main constituents of the raised lāyachīnī substrates. The results show that a dry mixture of the plaster of Paris and the red iron oxides are mixed with diluted animal glue to obtain a slurry to be applied in several layers, one top of the another, to achieve the raised substrates. This technique is similar to those European raised pastiglia substrates although the method of the preparation in the Persian technique is different from the European one

Colourants on the wall paintings of a mediӕval fortress at the mount Sofeh in Isfahan, central Iran

Colourants on the twelfth century wall paintings excavated at the fortress located on the mount Sofeh in Isfahan, central Iran, were analysed using micro X-ray fluorescence (µ-XRF), micro Raman spectroscopy (µ-Raman) and high-performance liquid chromatography coupled to electrospray ionization quadropole time-of-flight (HPLC-ESI-Q-TOF). The results of the analyses showed that gypsum, atacamite, carbon black, orpiment and ultramarine blue were used as white, green, black, yellow and blue pigments, respectively. Moreover, three red colourants including red lead, red vermilion and madder red were identified in the wall paintings. Furthermore, possible sources for the colourants are discussed

Organic Matter and Pigments in the Wall Paintings of Me-Taw-Ya Temple in Bagan Valley, Myanmar

Abstract: Pagán is an ancient city located in Myanmar that is renowned for the remains of about 4000 pagodas, stupas, temples and monasteries dating from the 11th to 13th centuries. Due to a magnitude 6.8 earthquake in 2016, more than 300 ancient buildings were seriously damaged. As a part of the post-earthquake emergency program, a diagnostic pilot project was carried out on Me-taw-ya temple wall paintings to acquire further information on the materials and on their state of conservation. This article presents our attempts at characterising the painting materials at Me-taw-ya temple using non-invasive portable energy dispersive X-ray fluorescence (ED-XRF), portable Raman spectroscopy and micro-invasive attenuated total reflectance—Fourier transform infrared spectroscopy (ATR-FTIR), micro-Raman spectroscopy (-Raman), gas chromatography-mass spectrometry (GC-MS), polarized light microscopy (PLM) and environmental scanning electron microscope—X-ray energy dispersive system (ESEM-EDS) investigations with the aim of identifying the composition of organic binders and pigments. The presence of a proteinaceous glue mixed with the lime-based plaster was ascertained and identified by GC-MS. In addition, this technique confirmed the occurrence of plant-derived gums as binders pointing to the a secco technique. Fe-based compounds, vermillion, carbo

Micro-Raman spectroscopy and X-ray fluorescence spectrometry on the characterization of the Persian pigments used in the pre-seventeenth century wall paintings of Masjid-i Jāme of Abarqū, central Iran

The pigments used in the wall paintings of the Masjid-i Jāme of Abarqū, central Iran, as less-known pigments used in the history of Persian painting, were investigated with micro-Raman spectroscopy, micro X-ray fluorescence (micro-XRF), scanning electron microscopy (SEM), and polarised light microscopy (PLM). The results showed that the green, red, and blue pigments were atacamite, red lead, and smalt mixed with natural ultramarine blue respectively applied on a white substrate composed of white huntite. Moreover, the blue smalt was identified to be used on the white huntite and under the paint layer in order to delineate the design of the wall paintings and to act as a rough sketch for the subsequent use of the other pigments. Glushinskite, as a less-reported mineral in historical wall paintings, was identified by micro-Raman spectroscopy and hypothesised to be associated with the degradation of the white huntite binder. Furthermore, micro-Raman spectroscopy studies surprisingly revealed the mineral woodhouseite sparely mixed with the green pigment. This paper strongly suggests micro-Raman spectroscopy for identifying archaeological pigments and for diagnosing their deterioration products. Conducting scientific methods of analysis, the pigments identified in this study are reported for the first time to be used in Persian wall paintings

A multi-spectroscopic approach to the characterization of early glaze opacifiers: Studies on an Achaemenid glazed brick found at Susa, south-western Iran (mid-first millennium BC)

This paper presents the results of micro-Raman spectroscopy, energy dispersive X-ray fluorescence (XRF), and scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS) studies performed on an Achaemenid glazed brick found at Susa (mid-first millennium BC). The results showed that calcium antimonate (CaSb2O6) and lead antimonate (Pb2Sb2O7) were used as white and yellow opacifiers in the white and orange glazes respectively. Moreover, the mixture of calcium antimonate and lead antimonate were used as opacifier in the green glaze. In addition, green, turquoise, blue, and orange colors were achieved by the dissolution of copper, cobalt, and iron-bearing materials in an alkali glaze. A black glazed line, whose color was obtained by copper and iron oxides, was used to separate the colored glazes. The present paper strongly suggests invasive micro-Raman spectroscopy for the identification of the opacifiers used in the early vitreous materials

Early Opacifiers In The Glaze Industry Of First Millennium bc Persia: Persepolis And Tepe Rabat

This study characterizes the opacifiers and colouring agents used in the glazed bricks of Persepolis (mid-first millennium bc) and the Mannean site of Tepe Rabat in north-western Iran (eighth to seventh centuries bc). Various analytical studies show that lead antimonate and brizziite (NaSbO3) were used as the yellow and white opacifiers in the glazes of Persepolis and Tepe Rabat. Brizziite is shown to be incorporated in the white, green and turquoise glazes, and is also associated with lead antimonate and CaSb2O6 in some yellow and white opacifiers. The simultaneous formation of these opacifiers in one glaze might have been accidental. A possible connection between the Achaemenid glaze industry and the Mannean glaze production at Tepe Rabat is discussed

A Technological Study of the Elamite Polychrome Glazed Bricks at Susa, South-Western Iran

This study investigated the technological features of the Neo-Elamite glazed bricks discovered at the Acropolis of Susa, south-western Iran, by conducting micro-Raman spectroscopy, differential thermal analysis/thermogravimetry (DTA/TG), X-ray diffraction (XRD) and scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM–EDS). The results showed that calcium antimonate white and lead antimonate yellow were used as opacifiers in the white, yellow and green glazes, and that green and turquoise glazes were achieved using copper. Coloured glazes were separated by a Si-rich brown glaze to prevent them from running together during firing. The glazed bricks most probably were not fired at temperatures higher than 900°C

To be or not to be local: a provenance study of archaeological ceramics from Shahr-i Sokhta, eastern Iran

Findings from the archaeological site of Shahr-i Sokhta in eastern Iran include a wide range of undecorated, monochrome, and polychrome ceramicswith gray, red, and buff-colored bodies that date back to a period spanning from 3200 to 1800 B.C.E. Given the large number and variety of ceramics unearthed from Shahr-i Sokhta, the provenance of these wares has remained a subject of controversy. Based on compositional data obtained from quantitative wavelength dispersive X-ray fluorescence (WDXRF) spectroscopy studies and petrographic observations, findings from this study provide information that can be used to determine whether the ceramics from Shahr-i Sokhta were manufactured locally or were imported from elsewhere. We show here that the chemical components of a large group of ceramics with gray, red, and buff-colored bodies are similar to those found in local clay sources and kiln wasters, suggesting local production of these wares. However, one group of red and gray-colored wares demonstrated entirely different chemistry, suggesting a different origin. In support of the quantitative WDXRF data, petrofabric analysis of the first group of buff, gray, and red wares revealed poorly sorted basaltic clasts similar to those found randomly distributed in the matrix of local clays. By contrast, the non-local gray and red wares exhibited fine-grained clay bodies with sorted distribution of fine-grained quartz within the clay matrix