What do dwarfs use as their currency?

Long time ago the dwarfs were exchanging mainly food which constituted major legal tender. According to that, during the reign of Krasnalis Vratislavis, who was the foremost dwarf king ever, the delivery of for example a letter by a pigeon keeper cost five thimbles of bread crumbs and sewing a new doublet was worth one cooked drumstick.As the times went by food began to disappear as a legal tender. Instead of food, the dwarfs started to exchange glass beads.  However, when it became clear that there are more and more glass beads available, they also lost their primary value. Dwarfs were showing great imaginative skills in developing new objects which could be used in counter trade. The customs related to exchange and counter trade were regularly changing depending on what used to be considered hardly accessible or luxurious at certain times. The precious goods had to be of course appropriately small so that they could fit into dwarfs’ wallets. During past centuries the dwarfs  were exchanging tobacco, porcelain, gold jewellery and several dozen years ago even… the bubble gum.  And that is how it goes until today.Perhaps providing dwarfs with credit cards would definitely change their lives. The problems is that no one’s willing to set up a dwarf account.