Alchemists use a rich symbology, which include elemental, planetary and mineral symbolism. In fact, the traditions of astrology, magic, tarot and many pagan rituals stem from the teachings of Alchemy.
One of the principal themes of symbolism in Alchemy is the union of opposites. This is expressed in many ways throughout the chemical as well as visual art. Such figures as The Elements, The Three Primes, The Seven Planets, the Twin Dragons and the Ouroboros (the great serpent of the universe eating its own tail) are widely used symbols in Alchemy.
In addition, the masculine principle is linked to the sun, gold and sulfur. While the feminine principle is considered lunar, and linked to silver and mercury.