Birthstones and Birth Flowers, Month by Month

The list is younger than it looks

Associating stones with months goes back a long way, and is usually traced to the twelve stones of the breastplate described in Exodus. But the list most people use today was standardised in 1912 by the American National Association of Jewelers to end the disagreement between competing regional lists. It has been amended several times since: alexandrite was added for June, tanzanite for December in 2002, and spinel for August in 2016.

That commercial origin explains the alternates. When a stone is rare, fragile or expensive — natural pearl, opal, alexandrite — the trade added an option that could actually be sold in volume. It also explains why a nineteenth-century family heirloom may carry a stone that no modern chart lists for that month.

Birth flowers, and why the lists disagree more

Birth flowers come from Victorian floriography, the language of flowers, which assigned meanings to blooms and tied them loosely to the months they appear in. No trade body ever standardised them, so British, American and continental European lists differ, and most months carry two accepted flowers rather than one.

The hemisphere matters here in a way it does not for stones. A May birth flower chosen for a northern spring makes little sense in a southern autumn, which is why lists compiled in Australia and South America often diverge from the northern standard.

Choosing a stone as a gift

Hardness decides how a piece will wear. On the Mohs scale, diamond is 10, ruby and sapphire 9, topaz 8, emerald 7.5 to 8, quartz stones such as amethyst and citrine 7. Opal sits near 5.5 to 6.5 and pearl near 2.5 to 4.5, so those two scratch and chip easily and are better suited to earrings or pendants than to an everyday ring.

If the assigned stone is impractical or simply not to the person's taste, the alternates exist for exactly that reason. Spinel for August and citrine for November were added as durable, affordable stand-ins, and nothing in the tradition ranks the primary stone above them.

Frequently asked questions

Why does my birthstone differ from the one my grandmother was given?

Because the list has been revised. Before 1912 several competing regional lists were in use, and amendments since have added stones to June, August and December. An older piece simply follows the standard of its day.

Is there a birthstone by zodiac sign as well as by month?

Yes, and the two systems do not line up. Zodiac stones follow sign boundaries that cut across the calendar, so a birthday on 25 April gives the April stone, diamond, but the Taurus stone, usually emerald or sapphire depending on the list.

Which month has the most expensive birthstone?

April, by a wide margin, since diamond carries the highest price per carat of the primary stones at gem quality. May is next with fine emerald, and June can rival both when the stone chosen is natural alexandrite, which is rarer than diamond.