Gemini is the third zodiac sign according to birth month. People born between May and June are more likely to choose the Gemini zodiac birthstone. The Gemini gemstone's birth date is between May 21st and June 20th. Gemini birthstones include pearl, alexandrite, tiger's eye, moonstone, and emerald. According to astrology, Geminis are fun and engaging. These jewels have a distinct history, importance, and therapeutic abilities that provide grandeur and knowledge.