Islamic glass is glass made in the Islamic world, especially in periods up to the 19th century. It built on pre-Islamic cultures in the Middle East, especially ancient Egyptian, Persian and Roman glass, and developed distinct styles, characterized by the introduction of new techniques and the reinterpreting of old traditions.Pinder-Wilson 1991, 112 It came under European influence by the end of the Middle Ages, with imports of Venetian glass documented by the late 15th century.Whitehouse 1991, 45
It rarely has religious content, other than inscriptions, although the mosque lamp was mainly used in religious contexts, to light mosques, but it uses the decorative styles of Islamic art from the same times and places. The makers were not necessarily Muslims themselves.
Though most glass was simple, and presumably cheap, finely formed and decorated pieces were expensive products, and often highly decorated, using several different techniques.Whitehouse 1991, 40-42 Muhammad disapproved of the use of tableware and drinking vessels made from precious metals, which remained usual for Christian elites in Europe and the Byzantine Empire. Islamic pottery and glass benefited from this, developing luxury styles in the absence of as much competition from ware in other materials, though some Islamic pottery reached the standards required for court entertainments.
The most important centres were Persia, Egypt, Mesopotamia and Syria through most of the period, with Turkey and India later joining them.
Roman and Sassanian influences Islamic glass did not begin to develop a recognizable expression until the late 8th or early 9th century CE, despite Islam spreading across the Middle East and North Africa during the mid-7th century.Israeli 2003, 319 Despite bringing enormous religious and socio-political changes to the region, this event appears to have not drastically affected the day-to-day workings of craft industries, nor did it cause "extensive destruction or long-lasting disruption".Schick 1998, 75 The Byzantine glass industry (Levant and Egypt) and Sassanian (Persia and Mesopotamia) glassmaking industries continued in much the same way they had for centuries, and glass was apparently still exported to the Byzantine Empire from the traditional centres, now under Islamic control.Jenkins, Marylin, "Islamic Glass: A Brief History," The Metropolitan Museum of Art Bulletin, New Series Vol.44 No.2 (Autumn 1986), 6. Following the unification of the entire region, the interaction of ideas and techniques was facilitated, allowing for the fusion of these two separate traditions with new ideas, ultimately leading to the Islamic glass industry.
Roman glassmaking traditions that are important in the Islamic period include the application of glass trails as a surface embellishment, while stylistic techniques adopted from the Sassanian Empire include various styles of glass cutting. This may have developed out of the long-standing hardstone carving traditions in Persia and Mesopotamia.Carboni 2001, 15–17Pinder-Wilson 1991, 115–122 In regards to glass-making technology, tank furnaces used in the Levant to produce slabs of raw glass for export during the Classical Period were used during the Early Islamic Period in the same region until the 10th or 11th centuries.Aldsworth et al. 2002, 65Freestone 2006, 202
Technological change
During the first centuries of Islamic rule, glassmakers in the Eastern Mediterranean continued to use the Roman recipe consisting of calcium-rich sand (providing the silica and lime) and mineral natron (soda component) from the Wādi el-Natrūn in Egypt, and examples of natron-based Islamic glass have been found in the Levant up to the late 9th century.Whitehouse 2002, 193–195 Much Roman glass had apparently begun as enormous slabs made in the Levant, then shipped to Europe for breaking and working. Archaeological evidence has shown that the use of natron ceased, and plant ash became the source of soda for all Islamic glass in the following centuries.Dussart et al. 2004Freestone 2002Freestone 2006Whitehouse 2002 The reasons for this technological transition remain unclear, although it has been postulated that civil unrest in Egypt during the early 9th century led to a cut-off in the natron supply, thus forcing Islamic glassmakers to look for alternate soda sources.Whitehouse 2002, 194
Evidence of experimentation with the basic glass recipe at Beth She'arim (modern Israel) during the early 9th century further supports this argument. A glass slab made from a tank mould from the site contained an excess amount of lime, and may be the result of mixing sand with plant ash.Freestone and Gorin-Rosin 1999, 116 Although the raw glass would have been unusable due to its composition, it does suggest that at this time, Islamic glassmakers in the Levant were combining aspects of Sassanian and Roman traditions in an effort to solve the problem created by the lack of access to mineral natron. The use of plant ash, specifically from halophytic (salt-loving) plants, which were plentiful in the Middle East due to the climate,Barkoudah and Henderson 2006, 297–298 was well known in Persia and Mesopotamia. It undoubtedly would not take long for the glassmakers in the Near East to correct their manufacturing errors and begin using the plant ash-based recipe used further east.
Early Islamic glass: mid-7th to late 12th century
The glass industry in the Early Islamic Period can initially be characterized as a continuation of older traditions, coinciding with the Umayyad Caliphate, the first Islamic dynasty (Israeli 2003, 319). Following the rise of the Abbasid Caliphate in 750, the capital of the Islamic world was moved from Damascus in the Levant to Baghdad in Mesopotamia. This led to a cultural shift away from the influences of Classical traditions, and allowed for the development of an 'Islamic' expression.Israeli 2003, 320
The production of glass during this period is concentrated in three main regions of the Islamic world. Firstly, the Eastern Mediterranean remained a centre of glass production, as it had been for centuries. Excavations at Qal'at Sem'an in northern Syria, Tyre in Lebanon,Aldsworth et al. 2002 Beth She'arim and Bet Eli'ezer in Israel, and at Fustat (Old Cairo) in EgyptScanlon and Pinder-Wilson 2001 have all shown evidence for glass production, including numerous vessels, raw glass, and their associated furnaces. In Persia, a formerly Sassanian region, archaeological activity has located a number of sites with large deposits of Early Islamic Glass, including Nishapur, Siraf, and Susa.Kröger 1995, 1–6 Numerous kilns suggest Nishapur was an important production centre, and the identification of a local type of glass at Siraf suggests the same for that site.Kröger 1995, 5-20
In Mesopotamia, excavations at Samarra, a temporary capital of the Abbasid Caliphate during the mid-9th century, produced a wide range of glass vessels, while work at al-Madā'in (former Ctesiphon) and Raqqa (on the Euphrates River in modern Syria) provide evidence for glass production in the region.Freestone 2006, 203Kröger 1995, 6–7 However, it is difficult to clearly identify the place in which a glass piece was manufactured without the presence of wastes (pieces broken and discarded in the process of making), which indicate that the location was a site of glassmaking. Furthermore, during the Abbasid caliphate, both glassmakers and their products moved throughout the empire, leading to dispersion of glassware and "universality of style", which further prevents the identification of a piece's birthplace. As the Seljuk empire arose from Seljuk generals conquering lands under the Abbasid flag only nominally, it is likely that glass technology, style, and trade might have continued similarly under the Seljuks as it did under the Abbasids.Ragab 2013 Despite the increasing ability and style of Islamic glassmakers during this time, few pieces were signed or dated, making identification of a piece's location of origin unfortunately difficult. Glass pieces are typically dated by stylistic comparisons to other pieces from the era.Lukens 2013, 199
The majority of the decorative traditions used in the Early Islamic Period concerned the manipulation of the glass itself, and included trail-application, carving, and mould-blowing. As mentioned previously, glass-carving and trail application are a continuation of older techniques, the former associated with Sassanian glassmaking and the latter with Roman traditions. In relief cutting, a specialized form of glass-carving most often used on colourless and transparent glass, "the area surrounding the decorative elements was carved back to the ground, thus leaving the former in relief".Pinder-Wilson 1991, 116
Unlike relief cutting, trail application, or thread trailing, allowed decoration with hot glass.Jenkins 2013, 28 The glassblower would manipulate molten glass while still malleable and create patterns, handles, or flanges. While cutting reached the height of its popularity from the 9th–11th centuries CE,Lukens 2013, 200 thread-trailing became more widely used during the 11th–12th centuries, when Seljuq glassmakers were considered at the height of their skill.Lukens 2013, 207
Mould-blowing, based on Roman traditions from the 1st century CE, is another specialized technique that spread widely throughout the Islamic Mediterranean world during this period. Two distinct types of moulds are known archaeologically; a two-part mould made up of separate halves, and the 'dip' mould, whereby the viscous glass is placed entirely inside one mould.Carboni 2001, 198 The moulds were often made of bronze,Carboni 2001, 197 although there are examples of some being ceramic.von Folsach and Whitehouse 1993, 149 Moulds also often included a carved pattern; the finished piece would take on the shape and style of the mould (Carboni and Adamjee 2002). With these advances in glassmaking technology, artisans began to stylize and simplify their designs, emphasizing designs with "no foreground or background" and "plain but beautiful vessels".
A final decorative technology that is a distinct marker of the Early Islamic Period is the use of painted lustre decoration. While some scholars see this as a purely Islamic invention originating in Fustat,Pinder-Wilson 1991, 124 others place the origins of lustre decoration in Roman and Coptic Egypt during the centuries preceding the rise of Islam. Staining glass vessels with copper and silver pigments was known from around the 3rd century,Carboni 2001, 51 although true lustre technology probably began sometime between the 4th and 8th centuries.Caiger-Smith 1985, 24Pradell et al. 2008, 1201 Lustre painting on glass involves the application of copper and silver pigments, followed by a specific firing that allows for the ionic exchange of Ag+ and Cu+ with the glass, resulting in a metallic sheen fully bound to the vessel.Pradell et al. 2008, 1204 Regardless of its specific origins, lustre decoration was a key technology in glass production that continued to develop throughout the Early Islamic Period, and spread not only geographically, but also to other material industries in the form of lustreware glazed ceramics.
Middle Islamic glass: late 12th to late 14th century