Mercury is the prince. He is not mature enough. He is very fickle. He tends to copy the planet he is with. The results given by mercury are difficult to predict.
In a horoscope, Mercury is always found close to sun (with the sun or one rashi before or after the sun). Mercury is the karaka for communication. Retrograde mercury creates communication problems. Salesmen, Good Orators have well placed mercury.
Mercury is the only planet that considers moon to be its enemy
Rashis ruled by Mercury: Gemini, Virgo
Mercury Exaltation Rashi : Virgo
Mercury Debilitation Rashi : Pisces
Nakshatras ruled by Mercury : Ashlesha, Jyeshtha, Revati
Mercury is karaka for : Education, Speech, Communication
Friends : Sun, Venus
Neutral: Jupiter, Mars, Saturn
Unfavorable rashis: Sagittarius, Pisces
Gemstone: Panna (Emerald)
Day ruled by Mercury: Wednesday
Numbers ruled by Mercury: 5
Marankarak house for Mercury: 7th house