Nick Szabo  🔑

Also drachma, shekels, etc. Many of these units of weight were in use for standard weights of gold and silver jewelry long before introduction of coinage. See ee.g. https://unenumerated.blogspot.com/2016/12/weigh-and-deliver-compensation-and.html …

Neat article. So it seems all these names were just another way to call some specificed weight of a commodity, which does not settle the question for why they created these.

Maybe something related to divisibility? It seems less appealing to create one such unit if they used shells. Why would you create a unit called shells2 equivalent to 1.5 shells?

It was the quantity by weight of metal that was the money. The form of the metal was for transactional convenience and sometimes for display. Some pieces of jewelry were, like later coins, of standard weight, others could be cut in arbitrary places and weighed.

Shells > USD?

Alas, cheap transportation and industrial era tools greatly inflated them and often made counterfeiting easy. Validation lore wasn't up to that challenge; secure validation became too expensive.