A rare pair of blue-glazed pottery jars. Tang dynasty (618-907)

Each raised on a solid, slightly flared foot, covered with a blue glaze of bright tone that continues over the short neck and lipped rim and stops in an irregular line to expose a white underslip and the pale pinkish-buff body, the interiors partially covered with a thin, clear straw glaze of greenish tone; with a pair of similarly glazed covers - 10¼ in. (26 cm.) high (2) - Estimate: $60,000 - $80,000

Provenance : Acquired in 1989.

Notes : While cobalt blue was much admired in Tang dynasty China it was usually employed sparingly, since good quality cobalt was expensive. The cobalt available in China contained manganese and tended to give a rather dull blue. In order to get a blue of the brilliance of that seen in the glazes of these two jars it was necessary to use imported cobalt, which was rather pure, containing only traces of copper and nickel. The cobalt brought into Tang China had to travel considerable distances from the Middle East and would have been very costly. However, when combined with a lead-fluxed glaze, this cobalt produced the beautiful sapphire blue seen on the current jars.

Fragments of Tang blue-glazed vessels excavated from the kiln site at Gongxian in Henan province are illustrated in Zhongguo taoci quanji -7 - Tang sancai, Shanghai, 1983, pl. 156. A blue-glazed jar of somewhat more squat shape, but also with a cover, is illustrated by R. Krahl, Chinese Ceramics in the Meiyintang Collection, vol. 3 (I), London, 2006, p. 271, no. 1294. See, also, the pair of jars without covers sold in these rooms, 21 September 2004, lot 185. Monochrome blue ceramics were scarce even in the Tang period, and the current pair of jars is particularly rare.

The result of Oxford Authentication Ltd. thermoluminescence test number P108u80 is consistent with the dating of this lot.

Christie's. Fine Chinese Ceramics and Works of Art. 17 September 2008. New York, Rockefeller Plaza. www.christies.com