Silver represented the moon, while gold was associated with the sun. Most versions of the gold alchemy symbol depict a round sun, often surrounded by a circle of rays. In alchemy, gold stood for the yellow metals and also for mental, physical, and spiritual perfection.

Above, the “chemical wedding” of Sun and Moon signifies both the chemical combination of two substances, and the philosophical union of two sets of contrary principles: the heat and dryness of the sun, with the coolness and moisture of the moon.

In "The Encyclopedia of Magic and Alchemy", Rosemary Guiley writes: “In alchemy, the Moon represents feminine forces and the feminine principle of the cosmos. According to Emerald Tablet, it is the archetypal Mother and is the supreme force known as One Thing. It rules the Below, while the archetypal Father, the Sun, rules the Above.

Sun and Moon stand for a hidden alchemist and nature work. Sun and Moon are, together with Ouroboros, the most enigmatic and ubiquitous hermetic symbol. Indeed Sun and Moon, Sol et Luna, represent the foundation of hermetic symbolism.

Because astronomy was closely connected to alchemy, especially in its early stages, it was believed that each planet ruled over its corresponding metal. This went as follows: The moon rules silver The sun rules gold