eli5: Why does it seem like every civilisation uses coins as currency even before there was a lot of mingling?

Question

I just saw a photo of old coins from like 1 or 2000 years ago and they are all round.
Why is it that they all use coins and not squares or something else completely?

In: Other

Answer 1

There were definitely other currencies (the first that comes to mind – [Lithuanian long currency](https://en.wikipedia.org/wiki/Lithuanian_long_currency) made of silver)

But coins won because they were durable, easy to carry and civilisations that were wealthier, traded a lot, sort of spread them