4 Reales - Ferdinand VI

The Potosí mint, operating at over 13,000 feet in the Bolivian altiplano, supplied the bulk of silver coinage moving through Spanish colonial trade networks during Ferdinand VI's reign. These cob-style pieces — the macuquinas struck under his name — were produced from hand-hammered planchets cut from silver bars, a method already considered archaic by mid-eighteenth century European standards but maintained at Potosí due to the sheer volume demands of the colonial economy.

Ferdinand VI himself took no particular interest in colonial monetary administration; the practical decisions fell to the Casa de Moneda's assayers, whose initials appear on the coins and whose accountability — sometimes enforced by prosecution — was the primary quality control mechanism.