第一件為私人收藏, 另參考四件在國外博物館
北宋, 磁州窯  
Northern Song, Ruyi-shaped porcelain pillow, Cizhou kiln
(the first item below is private property, the others are in museums)

(Porcelain pillows were common in the Song dynasty. This type of decoration is one of the very best; made at Cizhou kiln, it is second only to the white pillows of Ding kiln.)

(Reference) 參考
大英博物館  British Museum  - https://www.britishmuseum.org/collection/object/A_1936-1012-169
出光美術館  Idemitsu Museum of Arts, Japan - http://idemitsu-museum.or.jp/collection/ceramics/chinese_ceramics/02.php
Minneapolis Institute of Art, 美國 MIT  - https://collections.artsmia.org/art/6007/pillow-china
上海博物館  Shanghai Museum Collection - https://www.shanghaimuseum.net/mu/frontend/pg/article/id/CI00004643  (page takes time to load)