My recent trip to Japan allowed me to see many Chinese characters i.e., Kanji (漢字) and one thing that caught my attention was an extensive use of the radical "貝"(かい) on words/characters related to bartering and economy.
買う - buy
売る - sell (now the traditional Chinese character for this is "賣")
貨 - money/value so 貨幣 (かへい) and 通貨 (つうか) become currency
資 - also related to value so 資金 (しきん) is fund, 資本 (しほん) is capital and so on.
There are a LOT more to these characters with the radical "貝" and many of them have meanings related to money and value.
And "貝" means a shellfish, so I thought maybe ancient China used shellfish as currency. (at this point I've realized maybe this is a wrong stackexchange to ask this question, feel free to migrate.)
So what role exactly does a shellfish play in concepts that are related to value?