This is the lid of a small cylindrical reliquary of Dharma Raja ("righteous king") Rabten Kunzan Phak (1389-1442), who was the second Prince of Gyantse in the Tsang region of central Tibet. He was a prodigious patron of Buddhism and the arts. His architectural commissions included the Palkhor Chode Monastery built in 1418–1428 with its great Kumbum stupa built in 1427-1437.
Probably representing the eight prongs of a thunderbolt (vajra), the exterior of the lid has eight gold lozenges on a silver ground with cloud patterns. The overhang is inscribed in Lantsa script with the renowned mantra known as the Buddhist creed, Om Ye Dharma Hetu Prabhava Hetum Tesham Tathagato Hyavadat Tesham Cha Yo Nirodha Evamvadi Mahashramana Svaha ("Of those things which proceed from a cause, of these the Tathagata has told the cause, and also how they come to an end. This is the teaching of the Great Renunciate").
The gold interior of the lid has the dedicatory inscription, "Enshrined in this casket is a relic of Dharma Raja Rabten Kunzan Phak (spelled Rab-brtan Kun-bzang ‘Phags)—who was an incarnation of Buddha Maitreya—and also his personal prayer beads which he used in completing the self-realization practice of the five-deity [mandala] of Yamantaka, and his amber necklace." Translation by Lobsang Lhalungpa. (Pratapaditya Pal, et al, Tibet: Tradition and Change [Albuquerque: The Albuquerque Museum, 1997], pp. 160-161, pl. 80).
