In the Tarot, the Star represents a woman pouring liquid, the water of life, from a silver pitcher into a gold pitcher.
The silver pitcher represents the material world; the gold - the spiritual one.
In alchemy, the energetic forces that animate the world are contained within the different metals.
The Sun governs gold, the precious metal above all others, which symbolizes perfection, the goal to be attained, an image of a new life.