10 Cash - Guangxu Mule

A mule in the strictest numismatic sense: obverse and reverse dies from two different intended coin types were paired together in error during production at the Kiangnan mint. The Kiangnan facility was among the most prolific and administratively chaotic of the late Qing provincial mints, operating under pressure to meet quotas while simultaneously managing die transitions across multiple denominations — conditions that made exactly this kind of pairing error possible.

Y#B140 is the standard reference attribution, though documented examples are rare enough that die-state analysis remains incomplete.