100 Cash - Xianfeng Yuanbao, Boo-yuwan

The Xianfeng reign (1851–1861) produced some of the most chaotic monetary policy in Qing dynasty history. Facing the catastrophic financial drain of suppressing the Taiping Rebellion, the court authorized a cascade of increasingly debased large-denomination cash coins — the 100-cash piece among the most ambitious. The Ministry of Public Works mint in Beijing struck these in brass rather than the traditional bronze alloy, a cost-cutting measure that the population recognized immediately and resented deeply.

Widespread refusal to accept large-denomination Xianfeng cash at face value was documented within months of issue. By 1855, many were circulating at a fraction of their nominal worth.