Jessica Rawson, 'The Surface Decoration of the Jades of the Chou and Han Dynasties', Oriental Art N.S, 21.1, (1975), 36-55.
Bluett and Sons Ltd. Early Chinese Art, Cunliffe Collection, London, 1973, No.85, pl. XVI.
Diameter: 21 cm Whole object, Diameter: 10.6 cm Hole, Thickness: 0.55 cm, Diameter: 10.6 cm Hole
Ayers and Rawson, Chinese Jade throughout the Ages (Victoria & Albert Museum 01/01/1975-31/12/1975)
Thomas Lawton, 'Chinese Art of the Warring States Period: Change and Continuity@ 480-222BC', (Washington,1982). 'Jades',pp.127-177
Far Eastern Art- Recent Gifts, Purchases and Loans. (Victoria & Albert Museum 01/01/1974-31/12/1974)
China, room 44
Cunliffe collection, Garner collection previously on loan to V&A
Ring with grain design
Eastern Zhou dynasty
Carved nephrite jade
From the Garner collection
Museum no. FE.22-1984 
Variegated green. A circular Bi ring of pale green nephrite jade, pierced centrally with a circular hole. The outer and inner rims have a a lightly raised beading on both sides. Both sides are worked with 8 bands of incised curls in low relief. The flat outer edge has remains of tooling marks at one point. Both sides carved with comma (grain) pattern all over.
The fact that the spirals align in a cross-grid has been shown by Jessica Rawson to point to an origin in the Chu culture area, and to a date not before the late 5th Century BC. The large size also points to a southern origin. A particularly close parallel with this example, cited by Rawson, is from Yangzishan, Sichuan (published KGXB 1956.4). Lawton argues that the precise decoration of these Warring States jades shows a shift of emphasis from ritual function to secular luxury.
A flat circular slab of jade with a large central hole is referred to as a 'huan'. It was a ceremonial object in ancient times, although how it was used exactly is unknown.