Mercury Stone Panna helps the natives of Gemini and Virgo to deal with all the negativity of Mercury. Mercury Gemstone Emerald helps in achieving great heights. Mercury is the factor of knowledge. This planet gives scholarship, and the ability to debate. Also, its effect affects the teeth, neck, shoulders, and skin of the person. The gem of this planet is Emerald which is green in color. Emerald is the gem of Mercury and Mercury is the lord of Gemini and Virgo.