A typologically interesting piece. Patina, tarnish.
Obverse: emperor's head in laurel wreath, to the right, in the rim legend:
ANTONINVS AVG PIVS P TR P XII;
Reverse: Annona standing left, holding two ears of grain and reaching out with her hand to modius, in the rim legend:
COS IIII;
Silver, diameter 18 mm, weight 2.19 g, axis 6 h.