If you're an alchemist, then you try to change common metals into gold. People have been trying to figure that out for a long time, so you might need to have another job to finance your career as an alchemist.
The word alchemist comes from alchemy, which has origins in the Greek word khemeia, meaning "art of transmuting metals." Active since ancient times, alchemists could be considered very early chemists because of their work trying to transform base metals into gold. Alchemists could also be considered wizards because they attempted to make special elixirs that would give everlasting life and cure sickness.