In your utopia, If you have small diamonds for money what would you call the money? It can't be diamonds

I would probably call them crystals

I'd probably refer to them as something to do with their shape or color but not a known word to make it original - maybe a mixture of two?

Such as, alphires, gemphyx, or just a combination of anything.

I feel creating your own word rather than using a word that has a meaning would make it seem like an actual new item rather than diamonds.