Technological application is one thing. The other thing is copper and silver got tarnish too quick. I have only discovered that only gold and platinum would be able to last longer enough for my elves, but those are quite rare.
Furthermore, I think this is a good opportunity to question this subject. I mean knowledge and what-if scenarios are what make us humans.
Petrified wood. They last forever. The challenge is to turn it into a coin. But you don't need to turn it into a coin. Items can be valuable and has fixed value as it is. Especially if your elves use it as 'petrified sacred wood' that can hold magic or some shit. It will instantly be valuable to people outside the area who uses worthless gold, silver and copper that can't hold magic.The elves in my fic lives a long life. Hence, I am having trouble finding a material that can last around 80-100+ before they have to be changed.
The typical materials are copper, silver, and gold.
With the exception of gold, silver and copper have crucial application to the technology so they are not used as currency.
What are the other candidates for coinage metals?
Then how about magic crystals as currency? That is the easiest way to have a valued currency that isn't tied down to value of metals.My magic system is too hard to have such inventive usage that can trivialise the scarcity of materials.
Also, do you need to follow the rules of physics in our world? For example, if all things have some magic in them, then they may last longer simply from the residual mana. Especially metals that are often conductive to mana.
Petrified wood. They last forever. The challenge is to turn it into a coin. But you don't need to turn it into a coin. Items can be valuable and has fixed value as it is. Especially if your elves use it as 'petrified sacred wood' that can hold magic or some shit. It will instantly be valuable to people outside the area who uses worthless gold, silver and copper that can't hold magic.
Or just use mana crystals.
Or maybe your elves got this huge magic tree that drops magic seeds every few weeks. They don't plant these seeds, but if they eat it, they can get instantly powerful for a short time. So they keep it with them in case they need it, but because they don't need it, it accumulated in their pockets. And thus they started using them as currency. Where before they just bartered.
I will think about that. Maybe because I feel it was too much of a hassle to change the bills every couple of decades.And why is that a problem? We use paper for money for Christ's sake. Have you ever seen a bill that has gone through the wash?
Dragon coins: Magic precast by a dragon that allows for certain spells to be cast. Each spell is contained in baked mud with powdered dragon scale. The ratio of dragon scale to mud determines the worth of the coin and mana contained within.If magic is a renewable resource in the world (or a lifeforce), I could see a material that acts as a container. The magic (whatever energy that might come in story-wise) preserves the container when full of magic, but the longer it holds it it consumes the energy. It is compliant towards the magic by absorbing it. That might also mean the material isn't malleable from alterations or equipped to be enchanted. It just sucks magic in and holds it in before running out of the energy (however long that takes) or until somebody intentionally draws it out for spells or whatever magical wonders that exist. Without magic, the material could degrade over time, but maybe magic restores it too? It'd be interesting to have this material sort of be an alternate form of life that has grown and adapted towards co-existing with magic in the world.
The "coinage" can be made of this material and the inhabitants of the world would know its worth by, maybe, glowing? Coins that light up when full of magic and are brighter (worth more) with higher quantities of magic in it.