1 Cash - Tự Đức Thông Bảo, zinc, Sơn Tây

Sơn Tây provincial issues occupy an odd corner of Vietnamese numismatics — cast rather than struck, and identifiable by mint marks that Chinese-trained court officials at Huế formalized under Tự Đức's administration. Zinc cash were a downstream consequence of chronic copper shortages that plagued the Vietnamese economy throughout the mid-nineteenth century, as the empire struggled to maintain a functioning bimetallic system while simultaneously financing campaigns against bandit confederacies in the northern provinces.

The Sơn Tây attribution rests on the reverse mint designation. Provincial casting quality varied considerably, and this mint's output is notably inconsistent in flan preparation.