Small Blue Dish with Purple-Red Splash (Jun Ware)

Artist Chinese , Henan province

Date12th century, Northern Song dynasty (960–1127) or Jin dynasty (1115–1234)

Mediumstoneware with optical blue lime-alkali glaze with a copper solution splash

Dimensions11.7 cm (4 5/8 in.)

ClassificationsCeramics

Credit LineStoddard Acquisition Fund

Terms

stoneware

Object number2008.47

DescriptionStoneware with optical blue lime-alkali glaze with a copper solution splash
Label TextJun ware, known for its sensuous, opalescent blue glaze, was first made at kilns in the Yu and Linru counties of Henan Province during the Northern Song dynasty. By the Yuan dynasty, Jun ware kilns had also been established in Hebei and Shanxi Province, and production is believed to have continued into the early 15th century. Jun ware consisted of mostly simple, unpretentious, robust stoneware shapes that became widely popular among the middle classes. This small circular dish was thrown on the wheel and provided with a hand-carved foot-ring. After biscuit firing, the body was coated with a layer of glaze, placed in a protective saggar and fired in a kiln (1250–1300ºC). The thick, high-silica lime alkali glaze, with its minute bubbles and slight surface pitting, was very difficult to produce. It required great control in measuring, selecting, grinding and mixing the raw materials, as well as a very long, high firing in reduction and a very slow cooling in oxidation. The blue color of the Jun ware glaze was mainly derived from an optical glass emulsion effect. During the firing and cooling process, the Jun glaze, with its carefully calculated silica and alumina levels, underwent a spontaneous liquidliquid phase separation. In this separation minute, well-dispersed, light-scattering glass droplets that were rich in calcia, iron and copper became suspended in the glaze matrix. This glass emulsion reflected blue light, while all other light waves passed through the glaze. Adding to the soft, diffuse appearance of the glaze, a thin layer of light-reflective anorthite (lime feldspar) crystals developed between the body and the ground of the glaze in the cooling process. When glazed and dried, but still unfired, this Jun ware dish (page 82, bottom image) was decorated with a copper-tin pigment splash. During firing at full heat, the splash merged with the underlying bluish glaze, turning red, purple, plum and sometimes even green. Early Jun wares had rather timid copper blushes, but later, especially during the Jin dynasty, these splashes became increasingly bold. While the technique is reminiscent of the earlier Tang dynasty splashed blackware (see 1953.82), the use of copper-oxide red makes Jun ware a precursor of the later oxblood, peach bloom and flambé porcelain glazes (see 1916.6, 1916.5, 1954.116, 1954.118.1).

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