Lustreware - Medieval Islamic Pottery Technique

Lustreware (less commonly spelled lusterware) is a ceramic decorative technique invented by 9th century C.E. Abbasid potters of the Islamic Civilization, in what is today Iraq. The potters believed that making lustreware was true  alchemy  because the process involves using a lead-based glaze and silver and copper paint to create a golden shine on a pot that contains no gold. Chronology of Lustreware Abbasid 8th c -1000 Basra, IraqFatimid 1000-1170 Fustat, EgyptTell Minis 1170-1258 Raqqa, SyriaKashan 1170-present Kashan, IranSpanish (?)1170-present Malaga, SpainDamascus 1258-1401 Damascus, Syria Lustreware and the Tang Dynasty Lustreware grew out of an existing ceramic technology in Iraq, but its earliest form was clearly influenced by Tang dynasty potters from China, whose art was first seen by those of Islam through trade and diplomacy along the vast trade network called the Silk Road. As a result of ongoing battles for control of the Silk Road connecting China and the West, a group of Tang dynasty potters and other craftsmen were captured and held in Baghdad between 751 and 762 C.E. One of the captives was the Tang Dynasty Chinese craftsman Tou-Houan. Tou was among those artisans captured from their workshops near Samarkand by members of the Islamic Abbasid Dynasty after the Battle of Talas in 751 C.E. These men were brought to Baghdad where they stayed and worked for their Islamic captors for some years. When he returned to China, Tou wrote to the emperor that he and his colleagues taught the Abbasid craftsmen the important techniques of paper-making, textile manufacture, and gold-working. He didnt mention ceramics to the emperor, but scholars believe they also passed along how to make white glazes and the fine ceramic pottery called Samarra ware. They also likely passed along the secrets of silk-making, but thats another story entirely. What We Know of Lustreware The technique called lustreware developed over the centuries by a small group of potters who traveled within the Islamic state until the 12th century, when three separate groups began their own potteries. One member of the Abu Tahir family of potters was Abul Qasim bin Ali bin Muhammed bin Abu Tahir. In the 14th century, Abul Qasim was a court historian to the Mongol kings, where he wrote a number of treatises on various subjects. His best-known work is The Virtues of Jewels and the Delicacies of Perfume, which included a chapter on ceramics, and, most importantly, describes part of the recipe for lustreware. Abul Qasim wrote that the successful process involved painting copper and silver onto glazed vessels  and then refiring to produce the lustrous shine. The chemistry behind that alchemy was identified by a group of archaeologists and chemists, led by who reported Spains Universitat Polità ¨cnica de Catalunya researcher Trinitat Pradell, and discussed in detail in the Origins of Lustreware photo essay. The Science of Lusterware Alchemy Pradell and colleagues examined the chemical content of glazes and the resulting colored lusters of pots from the 9th through 12th centuries. Guiterrez et al. found that the golden metallic shine only occurs when there are dense nanoparticulated layers of glazes, several hundred nanometers thick, which enhance and broaden the reflectivity, shifting the color of the reflected light from blue to green-yellow (called a redshift). These shifts are only achieved with a high lead content, which potters deliberately increased over time from Abbasid (9th-10th centuries) to Fatimid (11th-12th centuries C.E.) luster productions. The addition of lead reduces the diffusivity of copper and silver in the glazes and helps the development of thinner luster layers with a high volume of nanoparticles. These studies show that although the Islamic potters may not have known about nanoparticles, they had tight control of their processes, refining their ancient alchemy by tweaking the recipe and production steps to achieve the best high reflecting golden shine. Sources Caiger-Smith A. 1985. Lustre Pottery: Technique, tradition, and innovation in Islam and the Western World. London: Faber and Faber. Caroscio M. 2010. Archaeological Data and Written Sources: Lustreware Production in Renaissance Italy, a Case Study. European Journal of Archaeology 13(2):217-244. Gutierrez PC, Pradell T, Molera J, Smith AD, Climent-Font A, and Tite MS. 2010. Color and Golden Shine of Silver Islamic Luster. Journal of the American Ceramic Society 93(8):2320-2328. Pradell, T. Temperature resolved reproduction of medieval luster. Applied Physics A, J. MoleraE. Pantos, et al., Volume 90, Issue 1, January 2008. Pradell T, Pavlov RS, Gutierrez PC, Climent-Font A, and Molera J. 2012. Composition, nanostructure, and optical properties of silver and silver-copper lusters. Journal of Applied Physics 112(5):054307-054310.