Well readable details, dark patina.
Obverse: in the pearl rim a bust of the emperor to the right, in the outer rim a legend punctuated by a cartouche with the denomination 3:
FERD-III-D:G-R--I-S-A-G H-B-REX-;
Reverse: crowned imperial eagle in pearl rim, initials G-H at tail, legend in outer rim:
ARCHIDUX-A-DUX-B-M-M-C-T-1658;