What is the most successful currency in history, circulating for 1300 years, with a woman's fingernail print engraved on the back?

/kloc-The most successful currency in circulation for 0/300 years is Kaiyuan Bao Tong. This is when Tang Gaozu was in Wude for four years, he abolished the Sui Five baht and re-established this Kaiyuan Bao Tong. The woman's fingernail print was not intentional, but when she was making a coin mold, the concubine who was traveling with Tang Gaozu was curious and picked it up. Unexpectedly, before the mold was formed, she accidentally left a fingernail print.

The Tang Dynasty was the most powerful emperor in China, so it had the largest population and the most abundant treasury. Therefore, the national transportation was smooth, the circulation was particularly large, and because of the extensive transactions and fast circulation at that time, everyone had a lot of new coins in their hands. And mainly because this coin is durable and has high anti-counterfeiting technology, it has been circulated for 1300 years.

According to legend, Tang Gaozu once chartered Li Shimin, Li Yuanji and Pei Ji to build a stove, but they failed to build one separately. They have to work with Qi Xin, and both of them are indispensable. Therefore, after many discussions and confirmation, they made a set of molds and samples for Tang Gaozong. Because of the special love for Princess Qin at that time, even the emperor took her with him to gain insight on such an important matter. So there is the uncertainty of nail prints. After all, it is normal for women who stay in the harem to be curious.

Moreover, it was precisely because Princess Qin was very favored at that time that she was driven by curiosity to touch the coin mold, so she left her fingernail prints. At that time, the people who cast it didn't pay attention, so it has been handed down.