Oval glass-fronted silver pendant reliquary theca housing the first-class ex ossibus (of the bone) relic of Saint Asterius of Ostia, Martyr. The relic is affixed to a gilt paper starburst on a salmon-colored silk ground, surrounded by silver wire ornamentation, and identified in Latin on a fancy manuscript cedula label as Ex oss. S. Asterii Presbyt. & M. (of the bone of Saint Asterius, Presbyter & Martyr). On the back, the theca is secured with a seal of red Spanish wax bearing an imprint of a coat of arms of Fr. Francesco Maria Ginori (†1775), Bishop of Fiesole, Italy (1736–1775).
Saint Asterius of Ostia († ca. 222) was a martyred priest. According to tradition, he was a priest of Rome who recovered the body of Pope Callixtus I after it had been tossed into a well. Asterius buried Callixtus' body at night but was arrested for this action by prefect Alexander and then killed by being thrown off a bridge into the Tiber River. His body washed up at Ostia and was buried there. Asterius was venerated from at least the 4th or 5th centuries. His Feast Day is commemorated on 21 October.