Mercury

The structure of Mercury’s symbol is composed of three elements: the circle, representing the vital essence; the cross below, which signifies matter and grounding in the earthly world; and the horizontal crescent, symbolizing the mind and the openness to perception. Together, these three parts represent the union of body, soul, and spirit. The symbol originates as a representation of Hermes’ caduceus (Mercury in Roman mythology), the messenger god who moves across boundaries. The very idea of connection between worlds is already inscribed in its form.

In Astrology, Mercury’s symbol stands for communication, intellect, and exchange. The crescent above the circle represents the mind presiding over spirit, while the cross keeps the whole rooted in reality. It is the faculty of mediation, interpretation, and translation.
Mercury governs speech and exchange, as it rules over the power of words, the force that gives shape and life to thoughts, without which everything would remain abstract. It is the bridge between idea and expression, the messenger that transforms inner understanding into shared knowledge.