The present piece is remarkable for its vibrant swirling marble effect. Wares of this type, known in Chinese as jiaotai, were a Tang dynasty innovation created by twisting and kneading together different coloured clays. While a variety of ‘marbled’ vessels from the Song dynasty survives, those in the shape of a ball such as the present lot are relatively rare. An excavated ‘marbled’ ball is included in Dong Jianli, ‘Shandong Zibo Cicun yaozhi diaocha/An Investigation of a Kiln Site at Cicun, Zibo City, Shangdong Province’, Zhongyuan wenwu/Cultural Relics of Central China, 2010, no. 3, pp. 9-13, col. pl. 4(8). For an example of vessels with regulated patterns, see a small rounded bowl dated to the Song dynasty from the Xiaogushan guan Studio collection, exhibited in Rochers de lettrés, itinéraires de l'art en Chine, Musée Guimet, Paris, 2012, cat. no. 73.