Hong Kong, China Nicolas Chow of Sotheby’s holds a 900-year-old dish at an auction. The Imperial brush washer is just 13cm wide and hails from the 11th-century Ru kiln of the Northern Song dynasty in Henan, China. It has been sold for more than $33m (£25m), three times the expected price, to an anonymous buyer

Photograph: Jerome Favre/EPA