Zodiac Sign

Gemini

May 21 – June 21 · Air · Mercury

Traditional BirthstoneAgate (in ancient Hindu and Hebrew traditions), Pearl

Modern BirthstonePearl / Alexandrite / Moonstone

ElementAir

Ruling PlanetMercury

Associated crystals

AgateOpen in the Dictionary Tiger's EyeOpen in the Dictionary CitrineOpen in the Dictionary Clear QuartzOpen in the Dictionary AquamarineOpen in the Dictionary

Associated herbs

LavenderOpen in the Dictionary PeppermintOpen in the Dictionary FennelOpen in the Dictionary BacopaOpen in the Dictionary Lemon BalmOpen in the Dictionary

Source Tradition

In Ptolemy's system, Gemini is one of the houses of Mercury, part of the Air-triplicity (Gemini, Libra, Aquarius) governed by Saturn by day and Mercury by night. Agate appears in Exodus 28 as one of the stones of the High Priest's breastplate (Hebrew shebo), associated with Gemini by later commentators. Pearl entered the modern list for June in 1912, with alexandrite added in 1952 and moonstone recognized as an alternate.

Ptolemy, Tetrabiblos, Book I; Exodus 28:17-20; Jewelers of America, 1912 and 1952 updatesExplore sourcing notes in the Appendix