Page 33 - Lunyushanren Col II

STARS IN THE NIGHT SKY –
A RARE AND PRECIOUS JIAN WARE TEA BOWL

Rosemary Scott, International Academic Director Asian Art

The dark-glazed tea bowls made at the Jian kilns in the Song dynasty are important not only for their
beauty and technical innovation, as well as for what they tell us about tea culture, but also because
they are amongst the most internationally infuential ceramics of medieval China. They provided
inspiration for potters elsewhere in East Asia – notably Japan – and also, in later years, inspiration for
potters in Europe. The current bowl is one of a small group of Jian wares with an especially fne and
rare ‘oil spot’ glaze.

The black-glazed stonewares made at the Jian kilns in northern Fujian province differ from those
made at the kilns in north China, and indeed those made at the Jizhou kilns of Jiangxi province, in
the colour and texture of their clay body. Signifcantly, the Jian ware body has high iron content,
which obviated the necessity to use an iron rich slip on the body under the glaze, although there are
other compositional differences between the bodies found at the various Jian ware kilns. For example,
while those of the Daluhoumen 大路後門 and Yingzhangqian 營長乾 kilns were similar, the body at
the Anweishan 庵尾山 kiln exhibited some differences (see Feng Xiangqian, et al., ‘Provenance and
dating study on Jianyao Kiln porcelain bodies using NAA and WDXRF’, www.researchgate.net/
publication/290346851).

The great beauty of Jian wares lies in their glazes, which are fred between 1250-1350ºC, and are
largely similar to those of the northern black wares, but with a little more alumina to cope with the
higher fring temperatures. The glaze is overloaded with iron - c. 6%, while the maximum that a lime-
based glaze can dissolve is c. 5.5% - and the excess precipitates out. It is this precipitation which creates
the stunning visual effects in the glazes. The Jian glazes are also liquid-liquid phase separated glazes and
the formation of little glass droplets in the glaze during phase separation helps to carry the excess iron
to the surface. At the early stage of this process the droplets appear as tiny fecks giving the speckled
appearance of a ‘tea dust’ glaze. As the droplets move to the surface and burst they produce the effect
known as ‘oil-spot’ and then, if the glaze is allowed to run, it carries the burst droplets with it the
effect of streaking that is known as ‘hare’s fur’ is produced. The streaking is enhanced by the growth
of micro crystals in the excess iron oxide during cooling, and the varied colours of the different states
of iron oxide create the decorative effects.

The best known of the Jian ware glaze effects, where different colours of iron oxide provides delicate
streaks running down the sides of the tea bowls, is usually known as ‘hare’s fur’ 兔毫紋 in English, tu hao
wen in Chinese, and nogime temmoku 禾目天目 in Japanese. Much rarer are the glaze effects with spots,
rather than streaks, and which required catching the glaze at the point when the optimum spotting was
achieved, but before the glaze ran and created streaking. There are three rare and particularly prized
spotted glaze effects associated with Jian wares. The one known as ‘oil spot’ in English, yuteki 油滴,
literally ‘oil drop’ in Japanese, Chinese pinyin youdi, has shimmering iridescent spots, as on the current
bowl, which resemble clusters of stars against the night sky. Another spectacular spotted Jian glaze is
known as Yohen 曜変 literally ‘brilliant [kiln] transmutation’ in Japanese, and in Chinese yaobian 曜變.
In this glaze effect the spots themselves are dark but have iridescent halos. The third spotted Jian ware
glaze has dense white spots on the dark glaze, which were described by one Northern Song poet as
looking like melting snow on dark water. There is debate amongst scholars as to whether this latter
glaze or the ‘oil spot’ glaze is the one referred to in various historical texts as zhegu 鷓鴣 ‘partridge
[feather]’. There are at least seven different types of partridge in China with different markings, so it
is diffcult to be sure which the authors of historical texts had in mind, and indeed whether they are
consistent. However, Wu has pointed out that the Chinese Francolin Partridge has markings similar
to the Jian glazes with white spots (Marshall P.S. Wu, ‘Black-glazed Jian Ware and Tea Drinking in
the Song Dynasty’, Orientations, vol. 29, no. 4, April 1998, p. 29). Nevertheless, the ‘oil spot’ glaze is
more delicate and iridescent, and perhaps better evokes the appearance of feathers.

31 The Linyushanren Collection, Part II