Birthstone overview: How 12 gemstones became natal symbols

Very large smooth gem in green gold ring.

“You shall make a breast-piece of judgment … You shall mount on it four rows of stones; the first row shall be a row of ruby, topaz and emerald; and the second row a turquoise, a sapphire and a diamond; and the third row a jacinth, an agate and an amethyst; and the fourth row a beryl and an onyx and a jasper; they shall be set in gold filigree. The stones shall be according to the names of the sons of Israel: twelve, according to their names; they shall be like the engravings of a seal, each according to his name for the twelve tribes.”

Exodus 28:15

By the time the Israelites were exiting Egypt, gemstones had long been used for talismanic, devotional and medicinal uses. With that kind of beauty there’s no surprise they were ascribed importance.

In the epic of Gilgamesh, 2nd millennium BC, our hero on his quest finds a garden of the gods: “…all round him stood bushes bearing gems ... fruit of carnelian with the vine hanging from it, beautiful to look at; lapis lazuli leaves hung thick with fruit ... rare stones, agate and pearls from out the sea.”  Gilgamesh then recounts the myth Lugal-e (aka Ninurta's Exploits), a war in which the stones born to the monster Asakku fought against the gods. After winning the war, the gods divided the 49 stones into two groups, ordinary and precious, with the latter blessed by the gods.

Ancient Egypt believed in the curative powers of gems. The Ebers Papyrus, from about 1500 BC, recommends the use of lapis lazuli for eye salves – bonus: flattering as eye shadow – and hematite, an iron oxide, to check hemorrhages and reduce inflammation. Later it was believed that the curative virtues were enhanced when the gem was engraved with symbols or the image of a god.

Hindu astrology made the navaratna or ‘nine gemstones’ the most powerful of Hindu talismans and representing the celestial bodies of Indian astrology: Sun (ruby), Moon (pearl), Mercury (emerald), Mars (coral), Jupiter (yellow sapphire or topaz), Venus (diamond), and Saturn (blue sapphire) and the rising (zircon or hessonite) and descending (cat’s-eye chrysoberyl) nodes of the moon.

Not everybody bought into these theories. Pliny apparently was a sceptic as was Emperor Constantine the Great. Of the latter, Eusebius wrote in the 4th century that “He held that the varieties of stones so greatly admired were useless and ineffective things. They possessed no other qualities than their natural ones, and hence no efficacy to hold evils aloof; for what power can such things have either to cure disease or to avert death?” A scientist well ahead of the times.

Nonetheless, there’s no surprise that gemstones also took on a role as birthstones. G.F. Kunz, famed mineralogist and gem historian, notes that it is the 1st century writings of Flavius Josephus, The Antiquities of the Jews, where the connection is first made between the 12 stones of the high-priest’s breastplate in Exodus and the 12 months.

Despite the attribution, the connection between the breastplate and your gem is not, shall we say, written in stone. While the twelve Exodus gems appear to be clearly identified, the mystery of the actual gems used may never be solved. Interpretations vary, terminology changed, and without gemmological science often a name signified a colour not a species. Later in Revelation some of the 12 stones of the breastplate of the Second Temple changed. The above quote itself is interpretive, not definitive.

While the western genesis of gemstone attributions is biblical it took a couple of couple of millennia to solidify their association with birth months. The twelve gems were still linked more to curative powers, zodiacal signs and guardian angels before they were to birthstones. The wearing of natal stones only becomes commonplace beginning in the 18th century in Poland with the help of rabbis and Hebrew gem traders, states Kunz. 


Sapphire is one of the original gems of the Breastplate and has held a consistent role as a birthstone. Above, star sapphires set in 18k gold, by Disegno Fine Jewellery.


​Today, we are left with a number of birthstone traditions and options and the list continues to evolve. Ruby, a gem not known in Egypt during Exodus and thus certainly not on the breastplate, is now July’s stone. But it had been December’s. Oh, but before that it was July’s and all that time it was swapping places back and forth with turquoise. But move over turquoise: since the discovery – only in 1967 – of tanzanite, it too is an option for the twelfth month. So, not keen on your birthstone? Look around, there’s bound to be a list that gives you the gem of your desires.

All that being said, here’s the current North American standard list (with some alternate gems) as per the Gemological Institute of America:

January: Garnet
February: Amethyst
March: Aquamarine (bloodstone)
April: Diamond
May: Emerald
June: Pearl (alexandrite, moonstone)
July: Ruby
August: Peridot (spinel, sardonyx)
September: Sapphire
October: Opal (tourmaline)
November: Topaz (citrine)
December: Turquoise (tanzanite, zircon)


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