Chinese Works of ArtAN ETCHED AND DIAMOND-ENGRAVED SAPPHIRE-BLUE OVERLAY GLASS CUP, KANGXI, 1696-1715The square-shaped sweeping cup is made of sapphire-blue glass, with the inside completely covered in a very thin, turquoise-blue overlay, and the outside with an etched and neatly diamond-point engraved designChina, Kangxi period, 1696-1715The four sides delicately etched and engraved to depict four square reserves, each with precious objects such as a double gourd, a gu vase with a ruyi scepter inside, a fang ding bronze, a ding vessel, a large basket and many more, all below an wheel-cut band of floral and foliage scrolls.Engraving of this type was introduced to the Imperial workshops by the German Jesuit missionary, Kilan Stumpf. In 1696, Emperor Kangxi appointed Stumpf to supervise the establishment of Imperial glass workshops with the help of craftsmen drafted from glass-making centres in Yanshan and Guangzhou. Stumpf was renowned for his glass-making and enameling skills, and contributed to the Chinese glass-making tradition, the German technique of wheel-cutting and in particular diamond-point engraving. When studying this superb cup, it becomes evident that this was not only designed to serve a later purpose as a cup, a washer or even a small brush pot, but in the first place as training-object for the craftsmen working under the supervision of Kilian Stump during the early 1700s. The number of early European glass-making techniques applied to this tiny masterpiece is so large, that is seems almost impossible that they all have been executed to perfection: The ingenious shape of the glass body with its slanted lips, rounded edges, sprawling form, convex sides, slightly domed base and a an inside overlay of less than 1 millimeter (!!) thickness, applied with not the slightest default. On top of that comes the décor, skillfully created using diamond-point engraving and etching techniques. While the designs themselves might look clumsy to the novice, they are unequivocally at their earliest stages of development, thus narrowing the possible dating of this piece to a period from 1696-1715. The intense sapphire-blue color of the cup, which is a typical color used in very early works of Imperial Glass Works of Beijing, only adds further to this assumption.For a comprehensive discussion on the Imperial glassworks, see E. Byrne Curtis, 'Chinese Glass and the Vatican Records', Transactions of the Oriental Ceramic Society, 1992-93, vol. 57, pp. 49-58.Shape: Sprawling cup, the sides slightly convex, the lip slanted, the edges roundedWeight: 140,3 gramsDimensions: 6,3 x 6,3 x 5,8 cmCondition: Good condition with old wear, few small manufacturing flaws, one nick to lip polished, some very minor nibbling, some tiny air bubblesProvenance: United Kingdom private collectionLiterature comparison: Compare with three clear vessels, all unmarked and dated to the Kangxi period: a dish from the collection of Walter and Phyllis Shorenstein; and a pair of cups in The Corning Museum of Glass, New York, included in the China Institute of America Exhibition catalogue Clear as Crystal, Red as Flame, New York, 1990, pls. 10 and 11. An etched bowl dated to the late 17th century, formerly from the K.R. Malcolm, and Professor and Mrs. Plesh collections, was sold at Christies, 16 November 1998, lot 291, and is illustrated in Elegance and Radiance, Grandeur in Qing Glass, the Andrew K.F. Lee Collection, The University of Hong Kong, 2000, p. 262, no. 96.康熙年間點鑽寶石藍玻璃杯，1696-1715年方形寶石藍玻璃杯，內套綠松色料，外圍精巧點鑽設計中國，康熙時期，1696-1715年品相良好英國私人收藏