Updated: Nov 13, 2021
This coin has been identified to a reasonable certainty, to be a Yuán-Yōu Tōng-Bǎo. The coin is of a cash type, estimated to be 1 cash value. Coins of this type were a "universal currency", issued from 1086-1093 CE. During the 1st era of Emperor Zhezong (1077-1100 CE). Who was the ruler of the Northern Song Dynasty, from 1085-1100 CE.
The coin is appears to be possibly made of "white bronze", a bronze alloy containing zinc. With an estimated width of 24mm (0.945 in) and weight of 3.25g.Its rim is a conventional type, being relatively wide and raised. The central hole is a common type, with a square hole. The hole's rim is relatively thin, done to make way for the coin's Hanzi characters.
Historically this coin type was known to be produced in an impressive 19 mints, located in 11 providences. The list of providences included Ezhou, Jianzhou, Huizhou, Shizhou, Wanzhou, Hubei, Muzhou, Shuzhou, Hengzhou, Chizhou, and Raozhou. Including the military garrisons of the Tongyuan and Nanping Army.
The coin's characters are read clockwise, in Running Script. They read 元 (Yuan), 豐 (Feng), 通 (Tong), 寶 (Bao). It should be noted the Running Script is a semi-cursive form of Hanzi. It originated from the calligraphy of imperial court scribes, during the the Han Dynasty (202 BCE-220CE).
In regards to the reverse, this example is blank. Although reverse details were some what uncommon, until later dynasties. Coinage of the Southern Song (1127-1179) feature small reverse details, such as a "Star and Moon" charm. Other examples include a single Hanzi character, such as 元 (Yuan), 三 (San), and 六 (Liu). These character representing the "first", "third", "sixth" year of rule, respectively.