Xerjaon is the currency of the Empire. It is a unique substance that can easily transmute into other substances. It is highly sought after for creation and building. The Empire has perfected a technique to 'seal' its state, preventing duplication and making it not deteriorate over time. Unsealed Xerjaon is illegal as it is a massive hazard and disrespectful. Trading it merits death. It is one of the regulations the Empire handles rather than Empirians just self-regulating because it takes a more keen eye.