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: ).

As in ancient Greece, socio-economic conditions at the time were favourable to the adoption of coinage.

They are not found in coin hoards, and the probability is that all these are in fact funerary items.

Archaeological evidence shows that the earliest use of the spade and knife money was in the Spring and Autumn period (770-476 BC).

Aside from officially produced coins, private coining was common during many stages of history. Some coins were produced in very large numbers – during the Western Han, an average of 220 million coins a year were produced.

Various steps were taken over time to try to combat the private coining and limit its effects and making it illegal. Other coins were of limited circulation and are today extremely rare – only six examples of Da Quan Wu Qian from the Eastern Wu Dynasty (222–280) are known to exist.

Later imitations in bone, stone or bronze were probably used as money in some instances.

Some think the first Chinese metallic coins were bronze imitations of cowrie shells) were definitely used as money.The ratios and purity of the coin metals varied considerably.Most Chinese coins were produced with a square hole in the middle.Occasionally, large hoards of coins have been uncovered.For example, a hoard was discovered in Jiangsu containing 4,000 Tai Qing Feng Le coins and at Zhangpu in Shaanxi, a sealed jar containing 1,000 Ban Liang coins of various weights and sizes, was discovered.This was used to allow collections of coins to be threaded on a square rod so that the rough edges could be filed smooth, and then threaded on strings for ease of handling.