Gemini is an air sign. In Western tropical astrology, there are 12 astrological signs, and each of the four elements is associated with three signs of the Zodiac, which are always located exactly 120 degrees away from each other along the ecliptic and said to be in trine with one another. The air signs are Gemini, Libra, and Aquarius. The air signs are communicative, sharp, and intellectual, but also prone to overindulging in fantasy and theory.