1 Spesmilo

The spesmilo was a proposed international currency unit conceived within the Esperanto movement, championed most actively by René de Saussure — brother of the linguist Ferdinand. This 1912 issue was produced in limited quantities for use among Esperanto speakers as a functioning monetary instrument, not a souvenir, with the intention that participating businesses and individuals would accept it at a fixed rate against major currencies. The project never achieved critical mass.

Catalogued under the "X" (unofficial issues) prefix, it occupies an unusual legal category — privately issued but struck to a serious silver standard, not a medal weight.