Thus Mercury, as the planet nearest the sun, obtained Virgo, the sign adjacent to Leo, with the corresponding lunar house in Gemini; Venus had Libra (solar) and Taurus (lunar); and so for the rest.
Gemini is an air sign, and this is fundamental to understanding this sign's nature.
Gemini is compelled to share information with others.
Little acts of kindness are always noticed by Gemini, who doesn't miss any of the tiny details, but can often be oblivious to a train wreck in front of her.
Some astrologer's interpret this "twin" as a link to the spirit world, and interestingly enough, Gemini's may even have some talent for clairvoyant or medium work.