You might be aware of your own birthstone, perhaps those of your loved ones—but did you know that the history of birth stones reaches back thousands of years, and has changed from time to time?

The chart we know was approved in 1912 in Kansas City during the annual convention of the National Association of Jewelers, and includes the most commonly used color, as many of these gems come in a rainbow of colors.

January – garnet (deep red)

February – amethyst (purple)

March – aquamarine (pale blue)

April – diamond (clear)

May – emerald (deep green)

June – pearl (opaque white), alexandrite, and/or moonstone

July – ruby (red)

August – peridot (pale green)

September – sapphire (deep blue)

October – tourmaline (pink) and/or opal

November – topaz (yellow) and/or citrine

December – tanzanite (blue), zircon, and/or turquoise

Over the years, other gems have been associated with birth months in different time periods and geographical locations, but many overlap—for clarity, I will list them together in a “historical birthstones” chart below, referenced from George Frederick Kunz’s “The Curious Lore of Precious Stones.”

January – garnet, hyacinth

February – amethyst, hyacinth, pearl

March – jasper, bloodstone

April – sapphire, diamond

May – agate, emerald, chalcedony, carnelian

June – emerald, agate, chalcedony, turquoise, pearl, cat’s-eye

July – onyx, sardonyx, carnelian, ruby, turquoise

August – carnelian, sardonyx, moonstone, topaz, alexandrite

September – chrysolite, sardonyx

October –  beryl, aquamarine, opal

November – topaz, pearl

December – ruby, turquoise, chrysoprase, bloodstone

People used to (and still do!) wear their birth stones under the assumption that the gem’s metaphysical powers would be heightened when worn by someone born under that month. Ultimately, what you choose is up to you. My birthstone is ruby, but I was so excited to find that onyx was also associated with July—lately I wear onyx earrings because they’re beautiful, a unique choice but still meaningful to me.

In general, wearing your birthstone is said to bring luck, good health and protection from evil, but each stone has its own unique attributes. So, even if your classic birthstone isn’t quite right for you, or if you’re like me and had no idea that your birth month is associated with more than one stone, I encourage you to explore your options and find the one that speaks to you.