Alchemists believed that one substance could be canged into another. The Greek god Hermes was supposed to have started alchemy so it was called the Hermetic art and practised widely by the Greeks and Romans of the 3d century AD. When the Arabs conquered much of the East they developed the principles of alchemy even further and passed on to the medieval West via Spain.
According to Roger Bacon, alchemy is "...a Science teaching how to transform any kind of metal in to another...". It is not surprising therefore to find out that the main focus for the alchemist was to transform any metal in to gold. Because alchemists believed that everything in the world can be perfected they were attracted to the idea of making everything as perfect as it was in the Garden of Eden. Clearly their beliefs were strongly influenced by Christian thinking. Because they saw gold as being the perfect metal, they felt that all metals must be slowly changing into gold. Their intervention was seen as giving God a helping hand.