Birthstones, month by month

A tradition reaching back to antiquity

The idea of pairing a stone with each month of the year has very deep roots. Traces of it appear in the breastplate of Aaron described in Exodus — twelve stones for the twelve tribes of Israel — which early commentators mapped onto the twelve months and the twelve signs of the zodiac. The custom was then handed down, transformed, commercialised: the modern list we know today was largely fixed by American jewellers in 1912.

The twelve gems of the calendar

January: garnet, the traveller's stone, which legend says lit Noah's ark. February: amethyst, “not intoxicated” in Greek, long reserved for bishops. March: aquamarine, sailors' talisman against storms. April: diamond, “invincible” in Greek, a symbol of eternity ever since Maximilian of Austria offered the first diamond engagement ring in 1477.

May: emerald, stone of Venus, whose mines Cleopatra owned. June: pearl and moonstone, the two gems of moonlight. July: ruby, “king of gems”, worn into battle by Burmese warriors. August: peridot, the Egyptians' “gem of the sun”, mined at night on a Red Sea island — and some specimens come from meteorites.

September: sapphire, stone of wisdom and fidelity. October: opal and tourmaline, captive rainbow and gem of a thousand colours. November: citrine and topaz, two autumn golds. December: turquoise, one of the first gems ever mined by humankind, and tanzanite, discovered in 1967 and found in only one place on Earth.

Birthstone or zodiac stone?

Do not confuse the two: the birthstone follows the calendar month, whereas the astrological stone follows the zodiac sign, which straddles two months. The two traditions coexist and regularly contradict each other — precisely because they are traditions, not science.