Like using a chocolate bar as a means of payment. You can break it up into smaller chunks to purchase, and you can get random chunks back when you sell, but once they are separated from the main bar, they don't just stick back to the entire bar. The only way to make them all one bar is to melt it back together with a Coinjoin chocolate bar maker. The excess will be scrapped off and can be Atomic Swapped for future use.