mosaic tile

One of the largest religious buildings in the world, the shrine of Imam Reza is considered a huge treasure of architectural decorations spanning many centuries. Among these decorations, tilework can be regarded as the most significant decorative element in this collection. This vast collection contains unique works from Seljuk tilework to the contemporary period. Considering the role and importance of color in tilework, this research aims to identify the new and emerging colors of contemporary tilework and make a descriptive comparison with colors of the same family from previous periods, according to the scientific characteristics of these colors. Therefore, the aim of this research is to identify the palette and variety of new colors that have been added to this spiritual space. Now the question arises: which colors have appeared as a new palette in contemporary mosaic tileworks, and what are their characteristics? Based on field interviews with the master workers of Razavi traditional tile company and referring to library sources regarding the dates of installation and restoration of tiles, all mosaic tiles from the 1970s to the late 1990s were identified and photographed, and the findings have been evaluated using a descriptive-analytical method. Finally, the number of 135 color codes was obtained, mostly from the newly constructed courtyards and porticoes. These emerging colors belong to six different color families.

The description of the magnificent building architecture from the Kerman Qara Khitai period in the travelogues of people such as Marcopolo, Stack, and Sykes has caused that in recent decades, the study of the green dome building should be done in order to discover relics from that period. Since the only remaining effect of this building is a porch decorated with mosaic tiles and also the tiles cast from the building, and contemporary researchers have different opinions about the age of these decorations, In order to clear doubts, this research tries to take into account the dating of tiles of the Green Dome of Kerman. Therefore, in this research, three samples of building tiles from three different places have been studied using the thermoluminescence method. The results showed that the tiles each belong to different periods, so that the A-100 sample tile is less old than the other samples. This sample, which is related to the spiral tile of one of the columns on both sides of the porch, is related to the contemporary (Qajar) period, and the sample of the tile used in the frame on both sides of the gate (A-90) is older than the other two samples and is around the reign Timurian is installed in the building. The sample A-80 was installed in the building during the Safavid period. Therefore, it can be concluded that this building has undergone different restorations during the natural and unnatural events that history shows, and the tiles cannot be attributed to a specific period.

The Mosalla of Paein Khiaban of Mashhad is one of the largest and most beautiful historic mosallas in Iran, built at the order of King Suleiman I during the Safavid era. according to inscription on the tile of the central porch, the date of construction and completion of the building is 1087 A.H. The architectural structure of the building consists of a high central porch in the middle and two domed porticoes on the sides. Both the internal and external surfaces of the building are decorated with various architectural elements, such as stucco work, tile work, painting and muqarnas. Among the various decorative employed in this structure, the mosaic tiles of the mihrab are unparalleled in terms of beauty and sophistication. Laboratory analysis of the chemical composition of the glaze of the altar tiles using SEM-EDX method demonstrated strong agreement with findings from other researchers, indicating a continuity of the tile-making tradition and glaze production with similar technology throughout the Safavid era across various r regions of Iran. A petrological study of the mineral composition of the body of the tiles also revealed the use of a similar and appropriate mineralogical composition, paired with good firing in their production, which contributed to the strength and durability of the tiles. The pathology of the building and its decorations indicated that a combination of different physical, chemical and human factors caused the destruction and erosion of the structure and its decorations, including the mosaic tiles. Among these, human activities and irregular urban development surrounding the building, along withimproper and careless restorations, played the main role in the destruction and erosion of the tiles. Considering the importance and sophistication of the mosaic tiles of the altar, following laboratory studies, the tiles of this part of the building were conserved and restored. For this purpose, after the primary conservation measures through cleaning and consolidation, the missing parts were restored according to the principles and theoretical foundations of restoration in the method of complementary restoration through color-matching.

The evolution of skylights and the way light is transmitted to dome-houses has always been a chief concern in architects’ mind. In terms of development and technique, such an element has been neglected, however being of significance. This main part, which has a great artistic role in Islamic architecture ​​from the perspective of technique, form and position, has changed over time and improperly replaced with new patterns.
The present research is to answer the following question: How was lighting in the dome-house spaces provided through shabāk (jali or skylight) with regard to the promotion of dome-houses construction techniques in the Timurid and Safavid periods in terms of form, design and execution? This research is qualitative and the method of collecting information is based on field and library studies. For this purpose, mosques of the Timurid and Safavid periods in two cities were classified and then, by carrying out a field study, the mosques that had shabāk were examined and finally, three mosques in Timurid Yazd and two in Safavid Isfahan were selected. Here, the samples whose authenticity was not confirmed by valid historical documents nor were they approved by experienced masters were omitted.

Findings show that in comparing the architecture of domes from the Timurid to the Safavid period, the position of skylights has been transferred to the lower quarter of the dome (pākār section). In this section, due to the increase in the thickness of dome shells, it was possible to create more skylights. Furthermore, the size of the shabāk mosaic frames has increased and the former simple, rectangular forms in the Timurid era have been transformed into an ogival form, but the elegance of the designs in comparison to the Timurid mosaic shabāks has reduced. Here, as the shabāk mosaics have more consolidation, larger and double mosaics have been used. Adding hamil tiles to the margins of skylights has made them more visible from a distance and an instant recognition of the main surface and shabāk has been allowed. The combination of colors is an important matter in adjusting the amount of light in the Timurid period and due to technical advances in glaze making during the Safavid era, greenish-blue was added to the color combinations on the shabāks. In the mosaic shabāks of Yazd mosques, geometric patterns are predominant forms and they are independent of the dome decorations with fairly simple designs. In the mosaic shabāks of Isfahan mosques, arabesque and khatāi motifs are repeated in the half, and mirror-like in the whole. They are symmetrically placed in a frame.

The Mashhad Musalla is one of the largest and most beautiful historic musallas in Iran. Mashhad Musalla has been built during the Safavid Empire, ordered by Suleiman I. Tile's inscription on the Iwan of Musalla gateway gives the date of the end of construction, in the year 1087 AH. This monument is located at the east of Mashhad. The building has a high porch and two porticoes on both sides. Musalla of Mashhad is constructed of bricks and it was previously using for prayers of the two Eids. The building has been decorated with stucco decoration, tile-working, wall painting and Muqarnas. The building is decorated with stucco decoration, tile-working, painting and Muqarnas. The glazed tile decorations of the Mashhad Musalla include glazed haft-rang and mosaic tiles. During Safavid period, all religious buildings were embellished with tiling decorations. The most prominent decorative element in Mashhad Musalla is tile-working. The tiles in the Mashhad Musalla are predominantly white, black, blue, turquoise, green, yellow and brown. The subject studied in this paper is the creating colorants elements and identification of the chemical composition of the glazed tiles in Mashhad Musalla. Scientific and analytical research was done by Scanning electron microscopy in combination with energy dispersive X-ray microanalysis (SEM-EDX) and Polarized light microscopy (PLM). Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to determine the elemental compositions of the tile glazes. According to the results obtained, tin (II) oxide together with lead glaze has yielded white color, manganese oxide had been responsible for black color, cobalt (II) together with magnesium oxide and fluorine has yielded blue color, copper oxide was responsible of the turquoise color, lead glaze with the low content of iron oxides has yielded a brown hue, yellow color is attained by lead antimonite and copper oxide together with lead glaze had been responsible for green color. The comparison of the results of the chemical analysis of the Safavid glazed tiles in historic Musalla of Mashhad and results obtained by other scholars who have worked on the identification of the elemental composition of the glaze of Safavid tiles in the other monuments of Iran, indicated that the creating colorant elements were the same, with a little difference, during the seventeenth century and over the Safavid period in Iran. Finally, thin-section analysis under a polarizing microscope was applied to study the petrographic composition on the tile samples. The results of structural study and mineralogical composition of the body mosaic tiles of Mashhad historical Musalla by petrography method showed that the presence of Muscovite, Hornblendes, Biotite, Quartz and Feldspar minerals as the main crystalline phases within the samples. Based on the applied methods, the mineralogical analysis of tile bodies has revealed some considerable results on the composition of this kind of tiles. Apart from minor differences related to the groundmass composition, all the tile bodies examined by thin-section analysis show similar microstructure characteristics and analogous petrographic compositions. On the other hand, the results of the elemental analysis of the glaze of Safavid tiles and considering little difference between chemical composition of the Safavid glazed tiles of the Mashhad historical Musalla and the elemental composition of the glaze of Safavid tiles in the other regions of Iran, it can be deduced that the raw materials used have probably been provided from the local resources.