The sun is the light of the world and naturally was viewed as the supreme celestial light by most ancient civilizations. Its glyph is the sun with a dot or circle inside:
It’s classical name, Sol, gives us the world solar. To be overly clear, many planets and solar systems may have suns, our sun is named Sol, just like many planets have moons but our moon is named Luna.
As the moon rules over the night, the sun obviously rules over the night, the un obviously rules over the day and shares virtually all of its associations: activity, light, righteousness, and life itself. The sun is an obvious metaphor for the soul and the fire of life that burns inside of us all. The light and heat from the sun literally sustain all life on this planet. The energy from the sun is the masculine seed that pierces into the female earth and renders it fertile. Most solar deities are male and the sun is generally viewed as masculine in contrast with the feminine moon.
The sun’s emissary on the zodiac is Leo, and it shares most of its symbolic connotations with Leo: powerful, regal, honorable. The sun has naturally been a metaphor for the king as long as there have been kings. Even in ancient Egypt thousands of years ago rulers identified with the sun. This single luminary eclipses all other heavenly lights and reigns unchallenged. Not all the planets are associated with an element, but the sun has a kinship with fire and shares many of its positive qualities, such as luminosity.
The metal associated with the sun is gold. Gold has an obvious visual similarity to the sun in that it is lumious, and even has has the hue of golden sunlight. Gold is also like the sun in that it is universally loved and viewed as supreme in its domain. In western culture gold has always been seen as the highest and most revered metal. Aside from its aesthetically pleasing nature, gold is also incorruptible, it will not degrade, erode, tarnish, or rust like other metals. One goal of the alchemists was famously to turn the other metals into gold. Some alchemists believed that gold was incorruptible because all of the elements inside of it were perfectly balanced. This harmony was also said to produce its unique beauty.
The sun rules over the energy of the sun and the energy of life in general. Its nature is energizing and stimulating.