20 000 Mark Steinkohlenbergwerk Gewerkschaft Neumühl

Zeche Neumühl was a coal mine in Hamborn, on the left bank of the Rhine just north of Duisburg, and by 1923 it was issuing its own emergency currency alongside dozens of other Ruhr industrial operations. The hyperinflation peak that summer made payroll in Reichsmark functionally impossible — denominations became obsolete faster than they could be printed and distributed. Mine operators, steelworks, and municipal authorities across the Ruhr filled the gap with Notgeld, often in denominations that would have seemed absurd eighteen months earlier.

The 20,000 Mark figure places this note firmly in the acute phase of the crisis, before the November 1923 Rentenmark stabilization rendered the entire series worthless overnight.