September Birthstone
Sapphire
"Wisdom, royalty, loyalty, and divine favor"
About Sapphire
Chemical Formula
Al₂O₃ + Fe/Ti (corundum with iron and titanium)
Crystal System
Trigonal
Hardness
9 on Mohs scale
Color
Blue (also pink, yellow, white, green)
Primary Origins
Sri Lanka, Kashmir, Myanmar, Madagascar, Australia, Thailand
Sapphire has meant something specific across almost every major civilization in recorded history: the sky, the divine, the truth. The ancient Persians believed the entire sky was blue because it reflected a giant sapphire on which the earth rested — which is a poetic way of describing a stone that feels like concentrated sky. Medieval clergy wore sapphires to represent Heaven; the Hebrews inscribed God's commandments on sapphire tablets in their religious texts; the ancient Greeks placed sapphires in Apollo's oracle seat at Delphi. This cross-cultural consistency suggests that the stone's blue color — which in the finest examples from Kashmir has a velvety depth that genuinely seems to contain light rather than just reflect it — has always done something to human perception that resists purely rational explanation. Sapphire is ruby's sibling — both are corundum, the same mineral, differing only in the trace elements that produce color. Where ruby's red comes from chromium, sapphire's blue comes from iron and titanium. The finest Kashmir sapphires, mined at altitude in the Himalayas from a deposit discovered in 1881 that was essentially exhausted within a few decades, are the reference standard against which all blue sapphires are measured: a saturated, velvety blue with a subtle violet overtone that seems to glow from within. Sri Lankan sapphires — the source of the Logan and Star of India sapphires at the Smithsonian — come in extraordinary variety, from the palest cornflower blue to deep inky tones, and include the extraordinary padparadscha, a pink-orange color that takes its name from the Sanskrit for lotus blossom. September birthdays have the most storied of the gemstone calendar.
History
Sapphire has been prized for at least 2,500 years. Ancient Persians believed the sky was blue because it reflected the color of a giant sapphire on which the earth rested [Kunz, G.F., 1913. The Curious Lore of Precious Stones]. Medieval European clergy wore sapphires as symbols of Heaven — the stone represented divine truth and royal dignity simultaneously. The Star of India, a 563.35-carat grey-blue star sapphire mined in Sri Lanka perhaps 300 years ago, is one of the largest and most famous star sapphires in the world, currently at the American Museum of Natural History. The 12-carat oval blue sapphire in Princess Diana's engagement ring — now worn by the Duchess of Cambridge — may be the world's most photographed sapphire.
Mythology & Cultural Traditions
The ancient Greeks associated sapphire with Apollo, the god of the sun and of rational order. Sapphires adorned the oracle's seat at Delphi. In medieval Christianity, sapphire represented Heaven — its blue color was the color of God's throne, the sky, and divine truth. The Ten Commandments were said to have been inscribed on tablets of sapphire. The ancient Hebrews believed the divine throne was a great sapphire, and the stone was included in the breastplate of the High Priest. In the Talmud, the stone was associated with chastity and the commandments of God.
Geology & Formation
Sapphire is corundum (aluminum oxide) colored by traces of iron and titanium. The blue color arises from charge transfer between iron and titanium ions in the crystal lattice — a quantum mechanical process that produces the characteristic blue. Corundum of any color except red is called sapphire; red corundum is ruby. The finest sapphires historically came from Kashmir (India), characterized by a velvety blue with a slightly violet overtone. Sri Lanka (Ceylon) produces a wide range of colors including the famous "padparadscha" (lotus blossom) sapphires in pink-orange. [Source: GIA Gem Encyclopedia, gia.edu; Mindat.org]
Famous Sapphires
The Star of India
A 563.35-carat grey-blue star sapphire, one of the world's largest, at the American Museum of Natural History. It displays a perfect six-rayed star and is believed to be about 2 billion years old.
The Logan Sapphire
A 422.99-carat faceted blue sapphire from Sri Lanka, one of the largest in the world, donated to the Smithsonian by Mrs. John A. Logan in 1960.
Did You Know?
Not all sapphires are blue. Corundum occurs in pink, orange, yellow, green, purple, and colorless varieties — all called sapphire except red (which is ruby).
Some sapphires display a six-pointed star called asterism, caused by intersecting needles of rutile (titanium dioxide) within the stone.
The world's most expensive blue sapphire sold at auction was the Blue Belle of Asia (392.52 carats) which sold for $17.5 million in 2014.
Care Instructions
Sapphire (Mohs 9) is one of the hardest and most durable gemstones — suitable for everyday wear in rings, bracelets, and earrings. Clean with warm soapy water and brush, or in an ultrasonic cleaner (for untreated stones). Avoid steam cleaning for heat-treated or fracture-filled stones. [GIA, gia.edu]
Frequently Asked Questions
What is the birthstone for September?
The primary birthstone for September is Sapphire.
What color is Sapphire?
Sapphire is Blue (also pink, yellow, white, green). Its chemical formula is Al₂O₃ + Fe/Ti (corundum with iron and titanium).
What does Sapphire symbolize?
Sapphire symbolizes Wisdom, royalty, loyalty, and divine favor.
How hard is Sapphire?
Sapphire rates 9 on Mohs scale on the Mohs scale.
Where is Sapphire found?
Sapphire is primarily found in Sri Lanka, Kashmir, Myanmar, Madagascar, Australia, Thailand.
How should I care for Sapphire jewelry?
Sapphire (Mohs 9) is one of the hardest and most durable gemstones — suitable for everyday wear in rings, bracelets, and earrings. Clean with warm soapy water and brush, or in an ultrasonic cleaner (for untreated stones). Avoid steam cleaning for heat-treated or fracture-filled stones. [GIA, gia.edu]
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