The symbol for Mercury is formed by a solar disc O topped by a crescent moon, and by a plus sign + which is not only the symbol of the earth, but also that of addition in arithmetic. For alchemists, this symbol also represents the four elements – two masculine elements and two feminine elements.

The Moon x represents water, the Sun ( fire, the plus sign + earth, and Mercury itself represents air.So, the Sun and the Moon give birth to the child, Mercury, the philosopher’s stone, which for alchemists is the symbol of the true transformation of man.

Omraam Mikhaël Aïvanhov