Internal corrosion of the metal - puffs on the surface.
Obverse: Bust of emperor standing right, in the rim legend HADRIANVS AVG COS III P P.
Reverse: Roma standing to the right, holding a spear, shaking hands with the emperor standing to the left, in the rim the legend ADVENTVS AVG
Silver, diameter 17 mm, weight 2.64 g.