1/4 Real - Philip II

The Potosí mint opened in 1572, established specifically to process silver from Cerro Rico — the mountain that would eventually yield roughly half of all silver mined in the Americas during the colonial period. Quarter reales from this early cob coinage era were struck by hand using rough blanks cut from cast bars, with virtually no concern for uniformity. Many surviving examples are so poorly centered that attribution relies almost entirely on partial die elements.

The MB#A1 designation signals this is among the earliest documented types from the mint's first decade of operation.