This is a brooch “Gold gab Ich Für Eisen”, or as is written officially on the reverse side of the medal: “Gold gab ich zur Wehr, Eisen nahm ich zur Ehr” (gold i donated for defense, iron i took for honor).
The core is an iron black painted medaillion. These were given to people who donated their gold items for the war effort of World War I in Germany. As the war was very expensive the German government (the army!) needed more money to finance the war. People were thus called to donate their jewelry and gold items. In return they got the medallion.
After the war (during?) many women let these black commorative medaillions be altered into brooches or even watch fob hangers. These were worn with pride to show the sacrifice they made for the war!
The here offered piece is such an into a brooch altered medaillion.
Very good condition, it is fitted in a real silver frame. A great piece of history!