AN EXTREMELY RARE SNOWFLAKE-BLUE CENSER MARK AND PERIOD OF XUANDE

superbly potted, the rounded sides supported on a small straight foot, gently rising to a slightly waisted neck, the exterior covered with a heavily mottled deep cobalt-blue glaze suffused with minute contrasting azure highlights, the interior and the underside glazed white, the base inscribed with a six-character reign mark within a double circle in underglaze blue

There is a long Y-shaped crack that runs from the rim stopping around 4 cm above the foot. The crack has an old rivet repair, that now has been removed and restored. There is also a small star crack on the side, visible on the interior. The foot has a 1 cm chip. The glaze is very well controlled and even throughout.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

No other snowflake-blue bowl of this form appears to be recorded, and the 'snowflake-blue' glaze as well as this bowl or jar shape are also outstandingly rare on their own. This low-fired mottled type of cobalt-blue glaze represents one of the most spectacular and surprising developments of the Ming imperial kilns in the Xuande period, and appears to have been one of the most difficult to fire successfully. Only eight other vessels with this type of glaze appear to have survived intact, seven of them thick-walled bowls of Xuande mark and period and one a bowl of the more common flared shape, without a reign mark. Recent excavations at the Jingdezhen imperial kiln site have, however, revealed extensive experiments in the Xuande period with this kind of glaze on a wide repertoire of shapes, including different types of dishes, bowls of various profiles, with thin and thick walls, stem bowls, narcissus bowls, and baluster jars, with and without incised decoration, but no example of the present form. Although the number of shards of this type recovered at Jingdezhen is also said to be small, more pieces appear to have been rejected than accepted by the quality control at the imperial kilns.

The glaze colour is known under various terms, such as salan ('speckled blue'), xuehualan ('snowflake blue'), or qingjinlan ('metallic blue'), of which the former term tends to be preferred in China, while the second has become popular in the West. The cobalt-blue glaze mixture is believed to have been blown directly onto the already fired but unglazed porcelain body, and to have been fired on at a lower temperature (around 800°-900° c), like cobalt-blue glazes on Tang earthenwares. This technique, as well as the mottled effect and the varied range of tones from a light turquoise blue to an intense lapis lazuli colour are unlike those of any other glazes developed in the early Ming dynasty. 

Extant examples are the snowflake-blue bowls with thick walls in the Capital Museum, Beijing, see Shoudu Bowuguan cang ci xuan [Selection of porcelains from the Capital Museum], Beijing, 1991, pl. 104; in the Freer Gallery of Art, Washington, d.c., published in Oriental Ceramics: The World's Great Collections, Tokyo, New York and San Francisco, 1980-82, vol. 9, no. 97; in the British Museum, London, from the Sir Percival David Collection, illustrated in Regina Krahl and Jessica Harrison-Hall, Chinese Ceramics. Highlights of the Sir Percival David Collection, London, 2009, pl. 34; in the Meiyintang collection, illustrated in Regina Krahl, Chinese Ceramics from the Meiyintang Collection, vol. 4, London, 2010, no. 1666; three others sold at auction: one at Sotheby's London, 16th May 1967, lot 95; one from the collections of Edward T. Chow and T.Y. Chao, illustrated in Geng Baochang, Ming Qing ciqi jianding [Appraisal of Ming and Qing porcelain], Hong Kong, 1993, col. pl. 16, sold in these rooms 25th November 1980, lot 50, and again 19th May 1987, lot 245; and a third also in these rooms, 1st May 2001, lot 510 (fig. 1).

No piece with this type of glaze appears to be preserved in the Palace Museum, Beijing, and the National Palace Museum, Taiwan, only holds an unmarked example of the more common bowl shape with thin walls and flared rim (fig. 2); see Catalogue of the Special Exhibition of Selected Hsüan-te Imperial Porcelains of the Ming Dynasty, National Palace Museum, Taipei, 1998, cat. no. 131.

Reconstructed fragmentary vessels from the Ming imperial kiln site were included in the exhibition Jingdezhen chutu Ming Xuande guanyao ciqi/Xuande Imperial Porcelain excavated at Jingdezhen, Chang Foundation, Taipei, 1998, cat. nos 15, 114, and f 33-35; others are published in 'Jiangxi Jingdezhen Ming Qing yuyao yizhi fajue jianbao/Brief Excavation Report on Imperial Kiln of the Ming and Qing Dynasties Located in Jingdezhen City of Jiangxi Province', Wenwu 2007, no. 5, pp. 4-47, pls 57-62, on the magazine cover and inside the back cover; and in Jingdezhen chutu Mingdai yuyao ciqi [Porcelains from the Ming imperial kilns excavated at Jingdezhen], Beijing, 2009, pls 61-68.

The snowflake-blue glaze was apparently abandoned soon after it had been developed and never properly revived again, although the powder-blue glaze of the Kangxi period may represent an attempt to recreate this effect. The Nanjing Museum holds a rare mottled blue censer of the Kangxi reign, which appears to have a similar glaze; see the exhibition catalogue Qing Imperial Porcelain of the Kangxi, Yongzheng and Qianlong Reigns, Art Gallery, The Chinese University of Hong Kong, Hong Kong, 1995, pl. 8.

The shape of this piece, described in Chinese with the terms bo or guan, is also extremely rare and no such piece appears to have been offered at auction before. A unique monochrome red version, with a cover, discarded at the imperial kilns, was included in the exhibition Taipei, 1998, op. cit., pl. 28, together with two blue-and-white examples, pls 29-1 and 29-2; two other covered blue-and-white bowls of this shape in Taiwan formed part of the exhibition Mingdai Xuande guanyao jinghua tezhan tulu/Catalogue of the Special Exhibition of Selected Hsüan-te Imperial Porcelains of the Ming Dynasty, National Palace Museum, Taipei, 1998, cat. nos 1 and 2. The blue-and-white versions all show a peculiar row of thick blue dots inside the rim.