640 Réis - Pedro II Rio de Janeiro and Pernambuco Mints

The 640 réis denomination was introduced under the Portuguese colonial monetary system as part of a broader effort to standardize coinage across Brazil at a moment when contraband silver and underweight pieces had badly eroded confidence in circulating money. Pedro II of Portugal — not the better-known Brazilian emperor of the same regnal name — authorized production at both Rio de Janeiro and Pernambuco simultaneously, an unusual dual-mint arrangement driven by the practical difficulty of distributing coin across such a vast colony from a single source.

The Rio and Pernambuco strikes are distinguished in the Bentes reference across more than a dozen catalogued varieties, primarily by assayer marks and subtle die differences. Pernambuco's output was the smaller of the two.