The September birthstone is sapphire, the blue variety of the mineral corundum. Its color comes from traces of iron and titanium, and at Mohs 9 it is one of the hardest natural gems. Sapphire is traditionally associated with wisdom, loyalty and clear thinking, and it has long been worn by royalty and given as a promise.
The stones
- Sapphire
Color: Blue · Birth flower: Aster, morning glory
September has a quieter feel than the summer months before it: the light turns clearer, the sky seems deeper, and the year starts to focus again. Its birthstone fits that mood. Sapphire is the gem of deep, steady blue, one that people have linked with truth and faithfulness for a very long time.
If you are looking up the September birthstone, you may be picking an engagement ring, a birthday gift or a keepsake. This page explains what sapphire is, the colors it comes in beyond blue, its symbolism, its history, how to buy and care for one, and which stones are traditionally tied to the zodiac signs born in September.
September birthstone: sapphire and its alternatives
The modern September birthstone, on the list maintained by the American Gem Society and Jewelers of America, is sapphire. September has one official stone, though it has several traditional and alternative companions.
Sapphire is a form of corundum, an aluminum oxide mineral. Red corundum is called ruby, and every other color is called sapphire, which means a sapphire can be blue, pink, yellow, green, orange or even colorless. When people simply say sapphire they mean blue. With a Mohs hardness of 9, it is among the toughest gems and well suited to daily wear.
Alternatives and traditional options include:
- Lapis lazuli, a deep blue rock streaked with gold-colored pyrite, named as a September stone on some traditional lists.
- Blue spinel, which offers a similar color at a lower price.
- Iolite, a violet-blue stone sometimes called water sapphire.
- Lab-created sapphire, which is real corundum grown in a laboratory.
Birthstone lists were standardized by the jewelry trade in 1912 and have changed since then, so older books and different countries often name other stones.
What color is the September birthstone?
The September birthstone color is blue. Sapphire's blue comes from tiny amounts of iron and titanium in the crystal. The finest stones are a rich, velvety medium-dark blue, and trade names such as cornflower blue are used for the most prized shades, especially from Kashmir and Myanmar. Sri Lankan sapphires tend to be a brighter, lighter blue.
Blue is not the whole story. Fancy sapphires come in pink, yellow, green, purple and white. The most unusual is padparadscha, a delicate pink-orange said to resemble a lotus blossom, a name from Sinhalese.
Some sapphires contain tiny needle-like inclusions that create a star effect, called asterism, when cut as a smooth dome. These are known as star sapphires.
Most sapphires on the market are heat treated to improve color. That is normal in the trade when disclosed, and untreated stones of high quality sell for a premium.
September birthstone meaning and symbolism
In crystal lore, the meaning of sapphire gathers around wisdom, loyalty, honesty and calm focus. Blue is the color of sky and deep water, and many cultures have used it for clarity and truth. People often wear sapphire as a reminder to think before speaking, to keep promises and to stay faithful to what matters.
Historically, sapphire was linked with royalty and with the clergy. Medieval writers connected it with heaven and with devotion, and it appeared in church jewelry and rings of rank.
It is also a stone of commitment. That is partly why sapphire is a popular alternative to diamond for engagement rings, and why it marks the 45th wedding anniversary in many lists.
Some modern crystal writers connect sapphire with the throat and brow chakras and with mental focus, though this is a recent tradition rather than an ancient one. All of these ideas are symbolic, not scientific. A stone cannot treat or prevent any illness or stand in for medical or mental health care. Treat the symbolism as a gentle prompt for reflection.
History of sapphire as a birthstone
Sapphire has been prized for thousands of years. The word comes through Latin and Greek from older roots, and writers in antiquity used the name for a blue stone that was probably often lapis lazuli rather than the corundum we call sapphire today. Corundum sapphires from Sri Lanka and India were traded for centuries, and Kashmir's brief mining history in the late nineteenth century produced stones still considered legendary.
Today major sources include Sri Lanka, Madagascar, Myanmar and Australia, along with Montana in the United States.
The idea that sapphire belongs in the Breastplate of Aaron is a popular one, but the link between the biblical stones and months is debated and developed centuries later.
The official September assignment comes from 1912, when the National Association of Jewelers, now Jewelers of America, published the first standard list, naming sapphire for September.
Sapphire has featured in royal jewelry for generations. A well-known example is the 12-carat Ceylon sapphire engagement ring chosen by Princess Diana in 1981, later worn by Catherine, Princess of Wales.
Choosing and caring for September birthstone jewelry
Sapphire is a very practical gemstone because it is hard and tough, so it works in rings, bracelets and anything worn every day. Focus on color first: a vivid, even blue with good brightness beats a very large but pale or dark stone.
To stay within budget, consider a smaller natural sapphire, a lab-created sapphire, blue spinel or iolite. Ask sellers to state whether a stone is natural, treated or lab-grown. Be cautious about very cheap sapphires, since glass imitations are common.
Care tips:
- Clean with warm, soapy water and a soft brush.
- Ultrasonic cleaners are usually safe for untreated or heat-treated stones, but not for fracture-filled ones.
- Store separately, as sapphire can scratch softer gems.
- Keep lapis lazuli away from water, acids and perfume, as it is much softer and more porous.
A sapphire gift pairs well with a small card explaining what the stone traditionally stands for.
September zodiac signs and their stones
September is shared by Virgo, through about September 22, and Libra, from about September 23. Zodiac stone lists vary a lot between sources, so this is tradition rather than rule.
Sapphire is often listed for both. For Virgo, the sign of care and precision, its calm clarity is a natural match, and carnelian and peridot also appear on some lists. For Libra, the sign of balance and fairness, sapphire's association with honesty suits the scales well, while opal and lapis lazuli are other popular choices.
If you are born in September, you have a stone ready-made. If a different color appeals to you more, there is no rule that says you must wear blue.
Frequently asked questions
What is the September birthstone?
The September birthstone is sapphire, the blue form of corundum. It ranks 9 on the Mohs scale and has been the official September stone since the jewelry trade published its standard list in 1912. Lapis lazuli is sometimes named as a traditional alternative.
What color is the September birthstone?
Blue. Sapphire's blue comes from traces of iron and titanium, and the most prized stones are a deep, vivid, medium-dark blue. Sapphires also occur in pink, yellow, green and other colors, but the birthstone is usually understood to mean the blue kind.
Does September have two birthstones?
On the modern American list, September has one stone, sapphire. Some traditional lists add lapis lazuli, and people often choose blue spinel or iolite as alternatives. Sapphire remains the standard answer for anyone asking what the September stone is. Choose by color.
What does the September birthstone mean?
In crystal lore, sapphire is associated with wisdom, loyalty, honesty and clear thinking. It has long been tied to royalty and promises. These meanings come from tradition, not science, and a stone is not a substitute for medical or mental health care.
What is the September birth flower?
The September birth flowers are the aster and the morning glory. Asters bloom in late summer in purple, pink and white, and morning glories open at dawn in blues and purples. Both have colors that pair nicely with a blue sapphire.
Angel number meanings are for reflection and inspiration. They are not predictions, and they are not medical, legal or financial advice.