Copper cash is the general terms of Chinese ancient currency made of copper which turned up in the Qin Dynasty (221 BC芒鈧€?06 BC), a dynasty leaving so many legacies to the Chinese people such as the Great Wall and the Terracotta Army. The copper coin is evolved from 芒鈧渉uan cash芒鈧劉 (莽沤炉茅鈥櫬? a kind of ancient copper coin with ring shape used in the Warring States Period which lasted from 475 BC to 221 BC). Generally speaking, most of the copper coins are round and there is a square hole in the center of the coin, hence there is another Chinese name called 芒鈧渇angkong cash芒鈧劉 (Fangkong, means square hole) and a nickname called 芒鈧渒ongfang brother芒鈧劉. People can distinguish different kinds of copper coins by the letters marked on the coins. These letters always refer to the region title in different dynasties, such as 芒鈧淨ianlong Tongbao芒鈧劉 (盲鹿戮茅拧鈥犆┾偓拧氓庐聺, Qianlong is one reign title lasting from 1736 to 1795, 芒鈧淭ongbao芒鈧劉 means the treasure in circulation) and 芒鈧淵ongzheng Tongbao芒鈧劉 (茅鈥郝嵜βＣ┾偓拧氓庐聺) in the Qing Dynasty (1616芒鈧€?911).