10 Pfennig - Frankenhausen

Frankenhausen's iron notgeld of 1918 belongs to the first wave of municipal emergency coinage forced by Germany's wartime metal requisitions — by mid-1917, copper, nickel, and zinc had been systematically stripped from the civilian economy for shell casings and military hardware, leaving hundreds of small towns to improvise local substitutes from whatever the Reich hadn't yet claimed. Iron was the unsatisfying answer. Frankenhausen, then under the administration of Schwarzburg-Rudolstadt, was one of dozens of minor principality towns that issued independently rather than waiting for centralized relief that never reliably came.

Iron corrodes, and surviving examples in collectible condition are genuinely harder to locate than the mintage figures might suggest.