These Imperial Germany silver coins were hoarded after WWI due to the high superinflation that occured soon afterwards.
The front of the coin reads "DEUTSCH REICH 1 MARK 187X", within an wreath.
The back of the coin depicts an eagle.
The coin is 800 silver and the split ring is 925 (sterling) silver.
Diameter: 23mm (15/16") - slightly smaller than a quarter.