September Birthstone: Sapphire

What is the September birthstone?

The September birthstone is sapphire. It is the only modern birthstone for the month, so there is no second stone to choose between, which makes gift-buying refreshingly simple. Sapphire has been the September stone on the standard birthstone list for over a century, and it remains one of the most popular coloured stones we set. If you are shopping for someone born this month, or reading up before you commit, our birthstones guide lays out the full year, and the notes below go deeper on sapphire itself.

Sapphire: colour, hardness, and everyday wear

Sapphire is a variety of the mineral corundum, the same mineral that produces ruby. When corundum is red, we call it ruby; every other colour of gem-quality corundum is a sapphire. Most people picture a deep cornflower or royal blue, and that is still the benchmark, but sapphire also occurs in pink, yellow, green, violet, and a soft pinkish-orange called padparadscha that collectors chase. Any non-blue sapphire is known as a fancy sapphire. Colourless sapphire exists too, and it was once used as a diamond stand-in before synthetics took over that job.

The reason we recommend sapphire so readily is durability. It sits at 9 on the Mohs scale, second only to diamond among the stones people wear daily. In plain terms, very little that your hand touches during an ordinary day is hard enough to scratch it. That toughness is why sapphire holds up in an engagement ring worn for decades, and why we are comfortable putting it in a piece that will not be babied. For a fuller comparison of how gem hardness translates into real-world wear, the International Gem Society's durability article is a sober, useful read.

The meaning and history of sapphire

Sapphire has long been associated with loyalty, steadiness, and a clear head, which is part of why it has turned up on royal and clerical hands for centuries. Medieval clergy wore blue sapphire because they read it as a colour of heaven and honesty. In more recent memory, the blue sapphire and diamond cluster ring worn by Diana, Princess of Wales, and later by the Princess of Wales, pushed sapphire engagement rings back into fashion in a way that has not really faded. We are careful not to sell you folklore as fact, but the through-line is genuine: this is a stone people have reached for when they want to signal constancy.

Choosing a September piece

Because sapphire is so hard, you have room to be practical about the setting. For a ring that will be worn every day, we like a bezel or a sturdy four-claw setting that keeps the stone secure without hiding its colour. If the birthday person already wears a lot of rings, a pendant is the easy win: it sits away from knocks, and a single blue sapphire on a fine chain reads as considered rather than fussy. Stud earrings are the safest first coloured-stone purchase, since ears take almost no abuse. A fancy yellow or pink sapphire is a good route if you want something that feels personal rather than expected. Whatever the format, we design and set these pieces by hand in our Coquitlam workshop, so we can match claw height and metal to the wearer's habits, and adjust a family stone into a new mount rather than forcing it. If the piece is also marking a milestone, note that sapphire is the traditional stone for a 5th wedding anniversary, and we build a lot of those; our bespoke anniversary pieces often start as a September birthday idea that grows. For broader background on the stones we work with, the gemstone guide is the place to start.

Caring for a sapphire

Sapphire is low-maintenance, but not no-maintenance. Warm water, a drop of washing-up liquid, and a soft brush lift the film of hand cream and skin oil that dulls any ring. Because the stone shrugs off scratches, the thing to watch is not the sapphire but the metal around it: claws wear thin over years, and a loose stone is how good gems get lost. We check settings free of charge when you bring a piece in, and we would rather re-tip a claw early than replace a stone later. Ultrasonic cleaners are usually fine for untreated sapphire, but many stones are heat-treated to improve colour, and a few are fracture-filled, which does not like ultrasonic cleaning, so ask us first if you are unsure what you have.

Frequently asked questions