Scientific Study of the "Robin's Egg" Glaze on an Imperial Vase of the Qianlong Period

1. Object of Study Object: Archaism-inspired vase with robin’s egg glaze and paired dragon-shaped handles, bearing an impressed six-character reign mark of the Qianlong Emperor. Archive Number: SS-REGL-VAS-007-QN Height: ca. 40 cm Provenance: Imperial Workshops, Beijing or Jingdezhen Period: Qing Dynasty, reign of the Qianlong Emperor (1736–1795) 2. Morphology and Stylistic Analysis The vase is executed in an archaism-inspired manner, reflecting the courtly taste of the Qianlong era. Its form—with globular body, elongated neck, wide flaring mouth, and stylised dragon handles—evokes ritual bronzes of the Shang and Zhou dynasties, reinterpreted through the lens of the haixuan (高宣) taste for mannerist antiquarianism. The vessel is made of thin-walled porcelain with a dense white body. The impressed six-character Qianlong mark on the base indicates its origin in the Imperial kilns of Jingdezhen. 3. Glaze and Manufacturing Technology Type of Glaze Robin’s egg glaze (lujun ci 鹿君瓷) — a low-temperature flambé-type glaze, created as an imitation of earlier Jun wares. Description Colour: Turquoise-blue ground with irregular mottling in purplish-red and violet tones. Texture: Multilayered, speckled, with a soft vitreous sheen. Application Method: Sprinkling or dripping technique, producing streaking and suffusion. Foot Ring: Narrow, with an unglazed band and traces of glaze run-off at the edges. Technical Reconstruction Component Function in glaze PbO (Lead oxide) Low-temperature flux K₂O, CaO Auxiliary fluxes CuO (Copper oxide) Turquoise pigment MnO₂ (Manganese dioxide) Source of purplish-red mottling Firing temperature: 900–1000 °C Kiln atmosphere: Reducing Technique: Double firing — high-temperature biscuit firing followed by low-temperature glaze firing in small kilns (xiao yao 小窑). 4. Comparative Analysis with Museum Examples The Palace Museum Catalogue: Chinese Ceramic Ware in Monochrome Glaze Exhibit No. 115: Vase of the Yongzheng period with robin’s egg glaze in dripping flambé technique. Exhibit No. 116: Vase of the Qianlong period, “cong” form, with identical glaze structure. Both examples confirm the technological and stylistic proximity of the present vase to imperial workshop production. “Robin’s egg glaze was a new type of glaze produced in the Imperial Kiln in Jingdezhen in the Yongzheng period... The basic feature was that the blue glaze dripped into vertical bands with deep red or blue mottles within the glaze. After firing, purple-red, blue, green, moon white and other colours merged and suffused together. Ware in robin’s egg glaze was characterised with reddish colour with a purplish tint, which resembled the colour of ripe Chinese sorghum and thus was named ‘Chinese sorghum-red’ glaze.”(Chinese Ceramic Ware in Monochrome Glaze, The Palace Museum, p. 5) This quotation confirms the key diagnostic features observed on the studied object: mottling, purplish-red and turquoise patches, vertical streaking, and pigment suffusion due to double firing. 5. References Chinese Ceramic Ware in Monochrome Glaze, The Palace Museum, The Commercial Press Zhang Yingyu. 南窑笔记 Nanyao Biji (Notes on the Jingdezhen Kiln), 1721–1803 Wang Qingzheng. A Dictionary of Chinese Glazes, Shanghai Museum, 1992 Kerr, Rose. Chinese Ceramics: Porcelain of the Qing Dynasty, Victoria and Albert Museum Medley, Margaret. The Chinese Potter: A Practical History of Chinese Ceramics Dronova, Nona D. Что надо знать о старинном китайском фарфоре [What You Need to Know About Antique Chinese Porcelain]. Moscow: OOO “Tipografiya KEM”, 2016, p. 239. DOI: 10.5281/zenodo.16794377. ISBN 978-5-9908782-6-6. 6. Conclusion Based on morphological, technological, and comparative analysis, as well as documented evidence from the Palace Museum catalogue, the vase can be identified as an authentic product of the Imperial Workshop of the Qianlong period, created with the rare multilayered robin’s egg glaze. This type of glaze is highly valued as an embodiment of refined courtly taste and represents a unique flambé variant with suffused pigment effects. The vase is of exceptional significance for both scientific research and collecting.