Gilded copper plate with repoussé work forming a mask representing one of the 84 Mahasiddhas. Could be Nāgārjuna. The face has an angry expression. The hair, eyebrows and beard have a black patina, each ear is fitted with a large ring, the forehead is adorned with five "snake" heads and an egg-shaped ushnisha appears on the top of the skull. A cloth covers the back of the mask-wearer's head. Tibet, 19th century H. 41 cm (accidents and oxidation, remnants of polychromy)