The sign of Gemini is linked to the planet Mercury.
Planets in Gemini affect the way in which that person uses logic and the way in which they communicate their ideas.
A person with the Sun in Gemini is likely to be especially successful in areas of life which requires which require good thinking and communication skills. They are very adaptable, and can easily modify their approach to suit changing conditions.
People with the Sun in Gemini are usually more intelligent than average. On the other hand, they are not keen to show their feelings until they know someone very well; and even then, they may seem rather detached. Despite this, they can be very charming, and often have a good circle of friends.