Cobalt is a stable periodic element found, among other places, in large ore deposits throughout continental Asia. Employed as a mineral pigment because of its vibrant hue, cobalt will consistently maintain its distinctive blue color even at the most extreme temperatures. Whether fired in an oxidizing or a reducing environment, it results in the same color, an attribute that makes it an especially useful coloring agent for porcelain.
Cobaltic ores are found locally in China, but imperfections in the native ore preclude the even tones necessary for refined ceramics. Beginning in the Yuan dynasty (1279–1368), Chinese potters began importing cobalt of a significantly higher quality from Persia (modern Iran and parts of Turkey). The pure cobalt refined from those western Asian sources was found to be much more consistent in producing the aesthetically desired luster and hue, and by the Qing dynasty (1644–1911), a strong commercial trade further linked the two ends of the continent.
This vase is a direct product of the effect of that mercantile arrangement on the output of the imperial porcelain workshops. The globular body is elegantly potted to taper into a broad cylindrical neck in an overall style reminiscent of the classic Chinese gourd. The exterior is uniformly covered in a thick, high-quality cobalt glaze that is as striking for its deep color as it is for its completely uniform tone. The interior is conventionally glazed in white as is the base, which is augmented by a six-character Qianlong reign mark, Daqing Qianlong nian zhi (made in the Qianlong reign of the Great Qing), in Chinese regular script. Together, these elements unite in a monochromatic celebration of form, color, and simplicity that is exemplary of the best tenets of Qing ceramics craftsmanship.