September has sapphire on both lists, and the traditional United Kingdom list adds lapis lazuli.
The two lists for September
Modern list (American Gem Society): Sapphire
Traditional list (United Kingdom, National Association of Goldsmiths, 1937): Sapphire, Lapis lazuli
There is no single official birthstone list, so you are free to choose whichever you prefer. You can check any month with our birthstone finder.
About the stones
Sapphire
Sapphire is corundum of any colour except red, best known in blue, which comes from traces of iron and titanium. Its hardness is 9. Sources include Sri Lanka, Myanmar, Madagascar, Australia and Kashmir, which is famous for a velvety blue. Heat treatment is widespread and accepted if disclosed, and sapphires also come in pink, yellow and other colours.
Lapis lazuli
Lapis lazuli is a deep blue rock rich in lazurite, mined in Afghanistan for thousands of years and ground into the pigment ultramarine. It is soft, at 5 to 5.5, and easily marked. See the lapis lazuli guide.
How the idea developed
Sapphire has long been the gem of September in the lists, and the traditional list’s companion stone, lapis lazuli, is one of the most ancient stones in use. The lists reflect the trade’s need for a simple chart, and that is why we say there is no single official birthstone list.
For the wider history of the idea, see our birthstones overview. The modern list follows the American Gem Society, and the traditional list follows the 1937 United Kingdom list, both summarised in Wikipedia, Birthstone.
A different system
Vedic gemstone (ratna) guidance is a different system from birthstones. It is tied to the nine planets and to a birth chart, not to the calendar month, and it belongs to the Vedic tradition, which is covered on our sister site, Nidarshana Vedh. Nothing on this page is Vedic advice.
A note on health. Crystals are valued for beauty, meaning and ritual. There is no scientific evidence that they treat health conditions. If you are struggling with your health or mood, please speak to a doctor.
Frequently asked questions
↳ Are all sapphires blue?
No. Sapphire comes in many colours. Red corundum is called ruby, and other colours are called fancy sapphires.
↳ Is lapis lazuli the same as sapphire?
No. Lapis is a deep blue rock, and sapphire is a transparent crystal of corundum.