60 Reis - João IV Countermarked 1/2 Tostão

João IV died in 1656, leaving Portugal mired in the long war of independence from Spain and chronically short of small silver. Brazil's colonial administration, facing the same shortage, was authorized to countermark existing Portuguese half-tostões — the 50 reis piece — revaluing them upward to 60 reis to keep fractional silver in local circulation rather than hoarded or exported. The countermark itself is the legal instrument; the host coin simply provides the silver.

Specimens vary considerably depending on the host coin's original condition and mint of origin, as coins from multiple Portuguese mints circulated in Brazil simultaneously.