A beautiful piece, a double minted piece.
Obverse: crowned royal monogram in the pearl rim, in the rim legend:
POTIORQ3 METALLO EST, in outer rim legend: DAT:PRETIVM:SERVATA:SALVS;
Reverse: in the pearl rim a crowned shield with the coats of arms of the Crown, Grand Duchy and Snopes, in the field of the shield the denomination XXX GRO/-POL-, on the sides of the shield initials A-T, in the outer rim the legend:
MONET:NOV:ARG:REG:POL:1663;