8 Reales - Philip IV

This is almost certainly a macuquina — a cob coin — struck at Potosí before the 1652 scandal that shut the mint down entirely. That year, an investigation revealed that assayers had been systematically debasing the silver for decades, substituting copper to pocket the difference. The fraud implicated the assayer general Ramírez de Arellano and reached deep into the colonial administration. Philip IV ordered the mint sealed, all circulating Potosí cobs recalled, and a new coinage struck under tighter supervision.

Coins dated 1652 may predate the closure or emerge from its chaotic final weeks. Assayer attribution on cobs of this period is frequently ambiguous.