Rivaling the renowned paintings created in the city of Siena in the fourteenth century are its masterpieces of goldsmith work, and The Cloister's chalice is one of the finest testaments to this accomplishment. Its base, knop, and stem are richly decorated with raised leafwork in gilded silver, enclosing gemlike figurative hexafoils of enameling. On the base is an image of Jesus on the cross, flanked by half-length figures of the Virgin Mary and Saint John the Evangelist. Three additional enamels represent Saint Louis of Toulouse, John the Baptist, and Anthony of Padua. The enamels on the knop represent Saint Michael, Saint Francis, an unidentified female, a female saint (probably Mary Magdalene), Saint Catherine of Alexandria, and Saint Elizabeth of Hungary. Two bands of inscriptions encircle the stem above and below the knop, and provide clues about the history of the chalice.

The inscriptions mention Brother Peter and the town of Sassofevrato. The name of Peter of Sassoferrato appears in the lists of Papal Penitentiaries appointed by Benedict XII, and resident in Rome in December 1341. He was an important figure in the Franciscan community during a period fraught with spiritual debate, heretical intrigue, and political posturing. He collaborated on Benedict XII's reform of the order in 1334, and was appointed Inquisitor at Assisi in July 1340. The Cloister's chalice seems to have been Peter's gift, or bequest, to the Franciscan community of his hometown, in whose possession it was recorded in the sixteenth century.