There was an interesting find in china the other day - all to do with the spade pieces from 700 BC or so.
There has long been a arguement over if these were the first currency pieces in the world or not - my own opinion is they are very similar to the bronze axe heads from the iron age and bronze age - they probably more served as a store of wealth (As in their copper value)
They are not true coins but can also serve as coins in a time of need , barter was probably a more common way to trade in those times .
The ancient greek silver , gold or electrum coins are at least true coins , I tend to favour these as the first true coins