It is extremely easy to fake cast Chinese cash coins, using precisely the same method of manufacture.
Normally, the method of manufacture will provide the clues to enable identification fake coins.
That is not the case with Chinese cast cash coins.
I have a card of 21 cash coins of the Northern Sung Dynasty (995-1119). Paid $10 for them, about 25 years ago.
40 years ago, I was buying as many different cash coins as I find, for 10 cents each. The reason why I wasn't prepared to pay any more per coin, is that I did not have the skill to separate fakes from the genuine coins.
I still can't.
These days cast cash coins may sell for more than $5 each. I am still not prepared to pay more that $1 per coin, due to my continued lack of skill to pick fake from genuine.
My collection of Chinese cast cash coins currently numbers at around 200, covering a period of around 2,000 years.
Despite all of the above, the study of Chinese cast cash coinage is a fascinating past time.
