Gemini ends spring. Mutable and air: the season is losing its shape and turning into the next, and the sign's traditional restlessness is that transition rather than a temperament.
Mercury rules it, as it rules Virgo — the same planet in two registers. In Gemini it is Mercury gathering and relaying; in Virgo, Mercury sorting and refining.
It is the last sign before the solstice, so the days here are the longest of the year in the northern hemisphere and still lengthening.
Traditionally attributed
Curiosity, versatility, talk, a low tolerance for finishing things.
Listed because it is what the tradition says, not because this site can check it. Everything above this line is geometry; everything in it is convention.