This bulbous-shaped vase with a slender neck and low foot ring has an incised Qianlong seal mark on its base. The cobalt and copper contents in the glaze were opacified with arsenic and when fired to a low temperature of about 700°C, these culminated in fine specks and streaks of blue. These trickled from the rim to the foot ring of this vase, further enhancing its bulbous form. Robin’s egg glaze is unique as no two same dramatic effects can be found on the wares it was applied on. This type of glaze, aptly termed transmutation glaze or “yaobian” is a spontaneous result of the reaction of glaze designs during firing. Developed from the opaque turquoise glaze, this is considered one of the technological achievements of Qing (1644–1911CE) ceramics.
