1 Cash - Xianfeng Tongbao, Boo-yūn, with crescent

The Xianfeng reign (1851–1861) was catastrophic for Qing minting. The Taiping Rebellion severed supply lines, debased coinage proliferated across provinces, and the Board of Revenue struggled to maintain any consistency in output. Yunnan's relative geographic isolation — and its proximity to copper sources in the southwest — meant the provincial mint continued striking when northern facilities had largely collapsed.

The crescent mark on this piece denotes a specific batch designation used at Boo-yūn. Its exact administrative significance remains incompletely documented.