In the web series Crash Course World History, it was said that coinage came into use in China, India, and Lydia all at about the same time, around 600 BCE. Did all of these regions come up with the idea of coins independently at about the same time? That seems like too much of a coincidence. Is it possible that the idea of coins originated in one area and then spread to other areas?
Lydia is hailed as having been the first to mint coins in 650s-ish BC. The first Lydian coins were beanlike, stamped with a lion head and made out of electrum.
The oldest known Indian coins are from 450BC and were punchmarked by circular and oval shapes. The coins themself were more like bars, bent by the punchmark process .
China 'coins' are totally different from Lydia and India. China started minting 'coins' 100yrs after the Lydians, they were in the shapes of miniature knives, forks, hoes and spades. Another important difference is the tools being used as currency were made in molds instead of being struck with dies such as was used every where else.
tl;dr We know they all starting producing coins because they were all made by separate processes and none of them had similar design.
