The Sogdian Trade and Use of Craft Materials
In our modern-day society where dyes and pigments are available cheaply and instantly, it is hard to imagine how difficult it would have been to produce the vibrant colors seen in mural paintings, textiles and ceramics of pre-modern times. Colorants, either organic or mineral, were often found only in certain geographical locations, and their transformation required specialized knowledge which made them highly sought after. In medieval Europe, the brilliant blue lapis lazuli pigment was more expensive than gold. In Asia, some colors and craft materials were just as rare and valuable, and the pan-Asian trade networks employed by the Sogdians contributed to spread them across vast expanses of land.
Trade records show that Sogdian merchants traded in a variety of craft materials. Around 600 CE, a scale-fee register was recorded to weigh and tax the goods carried by forty-eight merchants in the Gaochang Kingdom, in present-day Xinjiang, China (Hansen 2012: 99-102). Of the forty-eight merchants, forty-one have been identified as Sogdian. The register noted the weight of goods in order to calculate the appropriate tax to be levied. Made of paper, it survived by being reused as paper shoe soles, and despite its fragmentation, constitutes one of the best pieces of written evidence for trade along the Silk Road. The list includes raw materials for metalwork, such as copper, brass, silver and gold, as well as silk thread, to be transformed by local artisans in Central Asia and beyond. The record also lists one cargo of 17 kilograms of turmeric, a rhizome native to southwest India and used both as a medicine and as a brilliant yellow textile dye.
But by far the largest shipment recorded was a total of 187 kilograms of ammonium chloride. Also known as sal ammoniac, this chemical was essential to both textile production and metalwork. Diluted in water, it served as a mordant for textiles, combining with the dyes and fixing them onto the material. Mixed with metals, it acted as a flux, thereby reducing their melting point and making them easier to work. Finally, rubbed onto inlaid metalwork, it blackened brass and copper alloys while leaving the inlaid metals bright and shiny, thus heightening the contrast of the pieces.
Although no trade records for cobalt survive, it is highly likely that this mineral transited through Sogdian hands. Cobalt, which is naturally black but imparts a deep blue color when fired on ceramics and glass, was mined near Kashan, present-day Iran, and has been found on faience glazes of the Near East as well as numerous pieces of Islamic ceramics (Matin and Pollard 2015. Notably, it was first used as a glaze colorant on Chinese ceramics during the Tang dynasty. Since there were no known cobalt mines in China at the time, we can assume that this mineral was travelled across Central Asia, most likely through Sogdian hands.
Lapis lazuli, another rare and prized blue pigment, was mined in Badakhshan, a province in the northeast of present-day Afghanistan. In ancient times, this area was contiguous to southeastern Sogdiana, which made the mineral readily available to Sogdian artisans. As early as the sixth century BCE, a passage in the Charters of Susa, tablets that describe the various provinces of the Achaemenid Empire and the materials furnished by each for the construction of the palace of Darius I (522-486 BCE), mentions lapis lazuli: “The rare stones which (were) of lapis lazuli and also of carnelian [or cinnabar], which were worked here, were brought from Sogdiana” (De La Vaissière 2002, 18). Both of these minerals, especially lapis, could have been traded and used for inlay work, but were also frequently ground and mixed for mural paintings. In the eight century, we find traces of lapis lazuli, or ultramarine, as it was also called, in two far-removed sites on the Eurasian continent: mined in Afghanistan, the pigment was traded westward and used to color the walls of the San Saba church in Rome (Gaetani 2004). Closer to its origin, it colored bright backgrounds which give their name to the Blue Hall, a richly decorated room in a Panjikent house (Marshak 2002, 28).
Orpiment, a sulfuric mineral known for its bright yellow-gold color, was part of the yearly tributes of Kashgar to the Western Türk (Stark 2015, 472). Sogdians must have played a role in its trade, since it is found in paintings of the Temple II complex at Panjikent (Azarpay 1981, 163). Mixed with indigo, an organic blue dye imported from India, it produced the green color used to paint leaf scrolls on the hall walls of the same temple. The mountainous landscapes of Sogdiana were unparalleled sources of pigments derived from ferric deposits, such as yellow, orange, red, brown and purple. Cinnabar, which produced a vermillion red, was also found in the earliest paintings at Panjikent.
As traders, the Sogdians spread the use of pigments and craft materials across the Eurasian continent, propagating minerals such as lapis lazuli all the way to Europe, and cobalt all the way to China, in addition to engaging extensively in local trade networks. As artisans, they employed these pigments on the walls of their palaces, houses and temples, bringing to life the stories, epics and myths that made their culture unique. The vivid blues, reds, yellows, greens and oranges that the Sogdians used attest to their attunement to the aesthetic and dramatic possibilities of colors, visual effects that modern viewers can still experience today.
Azarpay, Guitty. 1981. Sogdian Painting: The Pictorial Epic in Oriental Art. Berkeley: University of California Press.
de La Vaissière, Étienne. 2005. Sogdian Traders: a History. Leiden; Boston: Brill.
Hansen, Valerie. 2012. The Silk Road: A New History. Oxford; New York: Oxford University Press.
Matin, Moujan, and Mark Pollard. 2015. “Historical Accounts of Cobalt Ore Processing from the Kashan Mine, Iran.” Iran: Journal of the British Institute of Persian Studies 53: 171–84.
Marshak, B. I. 2002. Legends, Tales, and Fables in the Art of Sogdiana. New York: Bibliotheca Persica Press.
Stark, Sören. 2015. “Luxurious Necessities: Some Observations on Foreign Commodities and Nomadic Polities in 6th to 9th Century Central Asia.” In Complexity of Interaction along the Eurasian Steppe Zone in the First Millenium CE, edited by Jan Bemmann and Michael Schmauder, 463–502. Bonn: Rheinische Friedrich-Wilhelms-Universität Bonn.