Coin

On the front, “Kaiyuan Tongbao” (the inaugural currency) is written in regular script. The back is blank apart from a crescent-shaped mark below the hole, which appears to be a fingernail mark. In the Tang dynasty, the weight of Kaiyuan Tongbao coins was regulated, with 10 wen (a currency denomination) equivalent to the weight of 1 liang (a Chinese tael) and 1 wen equivalent to the weight of 1 qian (a different currency denomination). This ushered in a new era in Chinese coin minting, and became the standard for the next 1,300 years.