Among nephrite jades of ink-black, spinach-green, celadon, yellow and white tones, it is the yellow jades that were considered as the most rare. As early as 1388, it is recorded in the Gegu yaolun, 'The Essential Criteria of Antiquities', that the best yellow jade should be stones with the "colour of the chestnut kernel, known also as pure (literally 'sweet') yellow, are the most valuable. The smoky yellow is the next in quality", see Sir Percival David, Chinese Connoisseurship, London, 1971, p. 120.
The varying yellow tones are very subtle and difficult to differentiate. Yang Boda distinguished the varying tones in Zhongguo Yuqi Quanji, Vol. 6, Hebei, 1991. The yellow jades of chestnut tone are particularly precious and valuable, such as the archastic baluster vase in the Palace Museum Collection, decorated with taotie masks between cicada motifs, ibid, p. 591, no. 204 (16.1 cm.) high. The supberbly carved archaistic motifs and the basic form of the present vase with its angled shoulder relate closely to the Palace Museum vase (fig. 1). The other categories of yellow are known as 'corn kernel', ibid, p. 588, no. 190, in description of a pear-shaped archaistic vase; 'sweet pear' yellow, a jade rhyton, p. 544, no. 41; 'interior with light celadon shimmer', a recumbent elephant supporting a vase on its back, p. 598. no. 235; and 'autumn mallow' yellow, in description of a cylindrical covered vase, p. 600, no. 241.
A majority of the jades made during the Qianlong reign were in imitation of archaic ritual bronzes of the Shang, Zhou and Han dynasties. The shape of some examples were more faithfully copied such as the yellow jade hu vase in the Palace Museum Collection, illustrated in Zhongguo Yuqi Quanji, vol. 6, Qing, Hebei meishu chubanshe, 1991, 180 (fig. 2); whilst others were slightly modified to suit prevailing taste of the Qing court (see fig. 1). The C-scroll finial on the cover and S-scroll handles are more likely to be Qing adaptations as are the elephant heads on the present vase. The form and motifs of the present vase were most probably inspired by similar archaic bronzes that had already been collected in the Palace. The closest example from which the present vase was used as a prototype is more likely to have been an archaic bronze hu, catalogued as the Zhou Bohe zun, and published in the Xiqing Gujian, 'Inspection of Antiques from Zhou Dynasty' (fig. 3). This publication was a compilation of Zhou period bronzes collected in the imperial palace, and appeared in its woodblock form in 1755 and published under the auspices of the Siku Quanshu, 'The Imperial Manuscript Library'.
It is interesting to note that Qianlong had written a poem dated to 1783 in praise of the Hetian jade that was made in imitation of the Zhou Bohe zun. In a sub-text it was recorded that the Zhou Bohe jade vase was bestowed to the son of Hesa Ke'apu Lebisi, who had previously entertained the Emperor to a banquet and his tribute of horses, see Qing Gaozong Yuzhi shiwen quanji, 'Anthology of Imperial Poems Written by the Qing Emperor Gaozong', chapter 4, juan 97, p. 19.