A nice piece of Prussian 4-penny. Patina.
Obverse: head of Frederick to the right, in the rim legend:
FRIDERICUS WILHELM BORUSS REX;
Reverse: crowned shield with the coat of arms of Prussia, on the sides the date 17-97, under the shield the denomination mark 4- GR-/A, in the rim the legend:
84 EX MARCH PURA COLON-;