Jade vessels of square shape appear to be quite rare. A white jade example with brown markings (13 cm. square), carved on two sides with a continuous scene of a scholar walking below the branch of a pine tree in a landscape setting, and on the other two sides with a poem describing the scene, as well as on the base with a poem by the Qianlong emperor, is illustrated in The Complete Collection of Treasures of the Palace Museum - 41 - Jadeware (II), Hong Kong, 1995, pp. 262-63, pl. 202, where it is dated Ming dynasty.