1000 Cash - Xianfeng Yuanbao, Boo-san, with Guan

The Xianfeng reign (1851–1861) produced the most chaotic coinage in Qing dynasty history. The Taiping Rebellion had severed southern revenue streams, and the Board of Revenue Mint in Beijing began issuing massive cash coins of inflated nominal value — 10, 50, 100, 500, and 1000 cash — as a fiscal emergency measure starting in 1853. The 1000-cash denomination was the largest, and public rejection was near-immediate; merchants discounted them heavily against face value, and the government suspended most large denominations within a few years.

The "Guan" supervisory mark indicates Board of Revenue oversight. Brass examples of this denomination are considerably scarcer than their cast-iron counterparts.