I don’t know about you, but I had quite the January. It was filled with fresh fruit, camels, wandering amongst buildings of past (and present) grandeur, and enjoying warm temperatures. No, I wasn’t in Iowa, but in India. Luther College provides us students with plenty of opportunities to study abroad during our January term, so I seized it. With nine other students and two professors we surveyed (or attempted to) Indian history. By having a hefty amount of background information on the sites we were seeing, we were transformed from tourists to travelers. One of the most interesting sites, by archaeological standards, were the mines of Zawar.Located in the ancient Aravalli hills, rich veins of lead and zinc ore course through the Zawar region just south of Udaipur, in Rajasthan. (670 km southwest of Delhi) The area sees continued exploration and mining efforts through several large mines operated by Hindustan Zinc. Radio carbon dating on wooden scaffolding in an ancient shaft has come back as 2120±60 years before present. While the mining of zinc and lead ore dates that far back, zinc smelting only appears just before the 7th c. CE. Zinc at one point in time was referred to as “Indian lead,” and for good reason too; zinc in its pure form was not produced in Europe until 1668 CE.
To extract pure zinc, the region became an inventor of the distillation and condensation smelting process. Zinc is notoriously difficult to refine to a pure metallic state, since zinc when melted escapes as vapor. The Rasaratnasamuccaya, a technical writing from the 14th century, provides a description of the distillation and condensation technique: "Place the chemicals in a vessel provided with a long tube, inserted in an inclined position which enters the interior of another vessel arranged as a receiver. The mouths of the vessels and joins should be luted with clay. Now urge a strong fire at the bottom of the vessel containing the chemicals whilst in the other vessels place cold water" (Ray 1956:190).
The retorts are truly formed as put forth by The Rasaratnasamuccaya. The upper retorts allow the melted zinc to flow into the collecting vessel of similar shape. Since the vessels filled with ore would be inverted, the fire would cover the entire smelting works. To avoid the heating of the coolant water, a large terracotta screen was placed on the coolant tank and under the retorts to be fired. The size of the retorts filled with ore provided a snug fit and further separated the fire from the screen.
One cannot walk without literally tripping over spent retorts. The retorts are so numerous that later locals built walls out of them (photo above), as their usefulness was exhausted. The furnaces in which the zinc was smelted also litter the landscape. Many lie buried in situ, undisturbed, but still quite visible.
Note: The Zawar region has a number of other sites and is an excellent day outing from Udaipur. Parts of the area have been excavated, mostly by the British Museum in the 1980s. The area is known for its “hundred” Jain temples and the Zawarmata temple.
P. T. Craddock, L. K. Gurjar, K. T. M. Hegde. Oct., 1983. Zinc Production in Medieval India. World Archaeology, Vol. 15, No. 2, Industrial Archaeology, pp. 211-217
Ray, P. 1956. History of Chemistry in Ancient and Medieval India. Calcutta. Indian Chemical Society.
