Ying Yuan (Chinese: 郢爰; pinyin: yǐng yuán) is one kind of gold coin issued by the mint of the Chinese state of Chu. The oldest ones presently known are from about the 5th or 6th century BCE. They consist of sheets of gold 3-5mm thick, of various sizes, with inscriptions consisting of square or round stamps in which there are one or two characters. They have been unearthed in various locations south of the Yellow River indicating that they were products of the State of Chu. One of the characters in their inscription is often a monetary unit or weight which is normally read as yuan (Chinese: 爰; pinyin: yuán). Pieces are of a very variable size and thickness, and the stamps appear to be a device to validate the whole block, rather than a guide to enable it to be broken up into unit pieces. Some specimens have been reported in copper, lead, or clay. It is probable that these were funeral money, not circulating coinage, as they are found in tombs, but the gold coins are not.