The astrological symbol of Gemini is the Twins.
Like twins, Gemini often have a dual nature and are skilled at seeing both sides of a problem, but they may also be fickle and restless. They are changeable and sometimes noncommittal. In this way, Gemini exemplifies the mutable quality assigned to it.

Gemini is ruled by the planet Mercury. In ancient Roman mythology, Mercury (and his Greek equivalent, Hermes) was the messenger god. He was associated with travel and transportation. He was a communicator, quick-witted and inventive, but he could also be a smooth-talker and get bored easily. As a planet, Mercury is androgynous; Gemini is the masculine (or day) half and Virgo the feminine (or night).
Both signs rule by words and logic, not emotion: Gemini is interested in communication as a way of making friends and learning, while Virgo is more focused on the analytical side, understanding what people are really saying. Mercury's role as communicator is exemplified in Gemini. People born under the Twins are charming and congenial, and they often have many friends and acquaintances in all areas of their lives. If they aren't careful, they may appear to be scheming or gossipy. Their facility in adapting to new challenges may seem like opportunism. Their interest in numerous subjects shows they are adaptable and curious, but they may seem like they lack concentration of have difficulty making decisions. Gemini who learn to focus and use their intellect in one area, instead of fidgeting, tend to be very successful.
The element associated with Gemini is air.
Air signs are intellectual. They tend to respond to the world through intellect, rather than physical action, practicality, or emotion. When presented with a new project, their mental abilities kick in and they join the group enthusiastically. While they don't tend to be leaders, their facility for abstract reasoning and broad-minded outlook enables Gemini to make strong contributions to projects they work on. Their logic and objectivity may help them see past roadblocks caused by emotional conflicts among others, but their intellectual orientation may seem cold and impractical to some. It is important for Gemini to learn that their love of knowledge can be compromised by their short attention span, but their awareness and intellectual approach to life can assist them.
As the Twins, Gemini is the sign of brothers and sisters as well as communication. They often remain youthful and light-hearted for their whole lives. Cars and short trips are also ruled by this sign, and many Gemini are mechanically inclined.
They are more likely to be ambidextrous than other signs, and can be inconsistent. Because they are "of two minds," people born under Gemini may tend to shift interests and seem scattered and high-strung.

In love relationships, Gemini is caring, flirtatious, and playful.
Gemini rules the collarbone, the arms and hands, the lungs, and the nervous system.
People born under Gemini may suffer from wrist problems, such as carpal-tunnel syndrome, respiratory ailments, and nervous conditions more often than people born under other signs.
Gemini's colours are yellow and sky blue, the colour of air.
The great strength of the Gemini-born is in their intellectual and conversational skills. They can analyze difficult ideas and communicate them clearly to others. Their many interests put them among the most fascinating characters of the Zodiac.