The Dongtian qinglu 洞天清錄 "Pure Records of the Cave Heaven", also called Dongtian qinglu ji 洞天清錄集, is a book on antiques written by the Song period 宋 (960-1279) scholar Zhao Xihu 趙希鵠. He came from Kaifeng 開封 (modern Kaifeng, Henan) and lived during the early Northern Song period 北宋 (960-1126).
The short book explains how to collect and appreciates antiques like zithers, inkstones, bells and ritual bronze vessels, strangely shaped stones, inkstone screens (yanping 硯屏), brush recks (bige 筆格), small water pots used for calligraphy (shuidi 水滴), autographs (hanmo zhenji 翰墨真跡), rubbings of stone inscriptions, colour prints and coloured paper (zhihua yinse 紙花印色) and paintings. Zhao Xihu's book is very helpful not only for the history of collecting antiques, but also concerning a lot of cultural objects whose use he explains, like diaodou 刁斗 (a kind of cooking utensil used during travels and military campaigns), bronze figures of real or fabulous animals that were used as oil lamps (and not as water dispensers, as often believed in his time). Zhu Quan 朱權, Prince Xian of Ning 寧獻王 of the Ming dynasty 明 (1368-1644), loved this book so much that he patronized its first print and marketization. The compilers of the imperial reprint series Siku quanshu 四庫全書 called this book a "compass for the connoisseur". The Dongtian qinglu is included in the reprint series Gezhi congshu 格致叢書, Tang-Song congshu 唐宋叢書, Xinang guangyao 奚囊廣要, Shuofu 說郛, Siku quanshu, Duhuazhai congshu 讀畫齋叢書, Haishanxianguan congshu 海山仙館叢書, Congshu jicheng chubian 叢書集成初編 and Meishu congshu 美術叢書.
Sources: Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, vol. 2, p. 1997. Changchun: Jilin daxue chubanshe.