4 Soles

Bolivia's 4 Soles denomination existed in an awkward monetary interval — a transitional issue bridging the old colonial macuquin tradition and the republic's gradual shift toward decimal coinage, which arrived definitively in 1864. The .667 fineness placed these coins below the old Spanish colonial standard, a deliberate reduction that allowed the Bolivian treasury to stretch silver reserves during a period of chronic fiscal instability driven by caudillo political turnover and interrupted mining revenues from Potosí.

KM#130 was struck at the Potosí mint, still the dominant source of Bolivian silver output a full three centuries after its founding under Spanish colonial administration.