37½ Reis Golden Vintém - Pedro I

The golden vintém — so called despite being struck in copper — took its name from the old colonial vintém coin worth 20 réis, with the 37½ réis denomination representing a fractional adjustment tied to Brazil's chaotic early monetary arithmetic following independence from Portugal in 1822. Pedro I's imperial government inherited a currency system layered with colonial-era accounting conventions that resisted clean decimalization, and this awkward fraction was the practical result.

KM#362 is frequently encountered with significant porosity and uneven surfaces, a consequence of Brazil's copper supply and casting practices at the time rather than circulation damage alone.