The earliest firm evidence for the production of metallic zinc is from
India. Of the metals used in antiquity zinc is one of the most difficult to
smelt since zinc volatalises at about the same temperature of around 1000oC
that is needed to smelt zinc ore. As a result it would form as a vapour in
the furnace which would immediately get reoxidised and hence lost. Hence
metallic zinc is seldom reported in antiquity. However in India there is
unique evidence for the extensive and semi-industrial production of metallic
zinc at the Zawar area of Rajasthan. An ingenious method was devised of
downward distillation of the zinc vapour formed after smelting zinc ore
using specifically designed retorts with condensers and furnaces, so that
the smelted zinc vapour could be drastically cooled down to get a melt that
could solidify to zinc metal. The Rasaratnakara, a text ascribed to the
great Indian scientist Nagarjuna, of the early Christian era describes this
method of production of zinc.
In Europe, the production of metallic zinc was virtually unknown until
William Champion first established commercial zinc smelting operations in
Bristol in the 1740’s following which it was industrially produced.
Interestingly the method of production adopted by downward distillation
bears a strong resemblance to the Zawar process and it has been pointed out
that Champion’s process was very likely inspired by the Zawar process which
would have been made known to the British during the forays of the East
India Company.
Another remarkable artistic innovation by Indian metalworkers of the past
was the use of zinc in making highly elegant bidri ware, an inlayed zinc
alloy, which came into vogue under the Muslim rulers of the Bidar province
in the Hyderabad region from about the 14th century. AD. Several impressive
vessels, ewers, pitchers, vessels, huqqa bases etc. were made of bidri ware
with patterns influenced by the fine geometric and floral patterns and
inlayed metal work of the Islamic world where decorative metalwork reached
some its most exquisite heights, for instance in the metalwork of the
Ottoman empire.