The most famous sapphire in the world may be the one on Kate Middleton‘s (and, before that, Princess Diana‘s) finger, but the gem also has the distinction of being September’s birthstone.
Like rubies, sapphires are part of the mineral species corundum—though unlike the former, they can come in just about any color of the rainbow (white sapphires, in fact, are an increasingly popular alternative to diamonds, since they tend to be more affordable). Per the Gemological Institute of America, the trace elements that result in the brilliant blue color most commonly associated with sapphires are iron and titanium, and the more there is of the former, the deeper the color will be. The rarest and most famous sapphires come from Kashmir, in the region north of India, while others are mined in Madagascar, Cambodia, Australia, and Vietnam.
As the second hardest gemstone, sapphire has historically been associated with fidelity and lasting love (hence its popularity in engagement rings), as well as bringing truth and wisdom to the wearer. Ancient Persians called it the “celestial stone” and believed that the Earth rested on a giant sapphire, which was reflected in the blueness of the sky.
Whether you’re celebrating a birthday this month or are just in the market for a piece of sapphire jewelry, shop earrings, bracelets, rings, necklaces, and more in the gallery ahead—starting at just $100.