The Meaning of gemini birthstone, often addressed by the lively agate, represents equilibrium, concordance, and security, mirroring the double nature and adaptability of those brought into the world under this zodiac sign.The sign of the zodiac for people born in May and June is Gemini. In particular, Geminis are those who were born between May 21 and June 21. After Taurus, Gemini is the third sign of the zodiac. The twins are the emblem of Gemini and the element of air. Being around Geminis is usually a complete pleasure because they may be witty, kind, gentle, and laid back.