CHINA KAI YUAN TONG BAO (792-907 AD) with extra mark

DescriptionKai Yuan was the main Tang dynasty coin type over three centuries. The extra dot means something, but we’re not sure what, perhaps a specific workshop, or who supplied the metal, etc.The Tang Dynasty is considered to be a cultural and political high point of Chinese culture. The borders of the country were expanded, especially to the west, and the regulation of commerce and some centuries of domestic security produced long periods of prosperity and the flowering of culture and science.The oldest Chinese coins are at least as old as the earliest Greek coins. The Chinese coinage system differed from other systems in two ways. It was monometallic, only bronze coins circulated in general commerce. Gold and silver were treated as commodities. And the manufacturing method was by casting in moulds rather than by striking heated solid planchets. The main reference I use in attributing and describing these coins is the book: Chinese Cast Coins, by David Hartill.