No, it isn't, but it could be added in. I could make them consume a maximum amount of silver per turn. For example, say you only want it to consume 3 silver per turn, then it could be done so that it will only eliminate a maximum of 3 silver per turn and increase the proportional gold. I might be able to make it require a worker to be in the building to convert to money; I suppose that would be better. I like the idea of only being able to send criminals to work on the Mint; after the revolution, it could be made so any unit could work there. tell me later if they helped.