Glass

After the Dwarves arrived in Foundation, their ability to mine more efficiently and smelt alloys better than other races caused a massive economic collapse throughout the realm. Shortly after, the Council of Peace met with the newly Arrived Dwarves and decided that Glass, a semi-translucent gem-like material that naturally occurs on the surface of Foundation and can be relatively easily formed into coins, would be the new standard of currency for all the nations of the realm. There are several colors with different rarities and values. This standard has remained in effect ever since. Metal still has a very high value on the open market but is not used as an international currency standard the way that Glass is.

Glass is a naturally occurring material that is similar to gemstones found deep under the ground. It is overwhelmingly clear, but some rare cases of colored Glass have been discovered and coins made from colored Glass is worth far more than the more common clear varieties. Glass is also evenly distributed and grows at a stable rate among all the land in each Ocean around Foundation, making it a great candidate for an international currency standard.