What Is Blue Sapphire? Color, Meaning & the September Birthstone
A Deep, Noble Blue — Blue Sapphire
Color · Meaning · September Birthstone · Collection
A deep, noble blue. Blue sapphire is a variety of corundum — second in hardness only to diamond — and has long been treasured among the most special of gemstones. From its meaning as a September birthstone to its natural unheated blue and the collection itself, here is an honest introduction.
See it in motion
What is Blue Sapphire
Second only to diamond in hardness — a deep, noble blue
Blue sapphire is a variety of the mineral corundum — the same species as ruby. Traces of iron and titanium give it a deep, clear blue. At Mohs hardness 9, it is second only to diamond, and reassuring for everyday wear. A gem of prestige, long loved by royalty and clergy.
The Story of Its Name
A stone meaning "blue"
The name sapphire is said to come from Latin and Greek words meaning "blue". Its deep, noble blue was set into rings and crowns as a symbol of sincerity and integrity, entrusted with special meaning across the ages.
On the Color, Honestly
This blue is a natural, unheated color
Most sapphire on the market is heated to deepen the blue and improve clarity — a common method. SMUK's blue sapphire, on the other hand, is unheated: we deliver the natural deep blue exactly as the stone holds it. Unheated sapphire is rare on the market, letting you enjoy a color only nature can give.
We believe in sharing the presence or absence of treatments, and the story of each stone, openly. We hope that knowing a stone's background lets you wear it with confidence, for a long time to come.
Meaning & Symbolism
A stone of sincerity and integrity
With its deep, noble blue, blue sapphire has long been cherished as a stone of "sincerity," "compassion," and "integrity." As a color that speaks to a steady, unwavering heart, it is chosen for gifts marking life's important milestones.
Stone Data
Blue sapphire is the birthstone for September — its deep, noble blue is a favourite gift for those born in September.
Birthstone September
Mineral Corundum
Hardness Mohs 9 (second to diamond)
Treatment Unheated
Origin Africa
The Blue Sapphire Collection
A collection pairing unheated blue sapphire with a base of Italian sterling silver 925 finished in rhodium plating. The deep, noble blue is set in a simple design, easy to wear every day.
Crowdfunded on Makuake
This collection ran a pre-order campaign on the Japanese crowdfunding platform Makuake, where it received the support of many backers. Thank you to everyone who supported us — the collection is now available on our official site.
View the Makuake project →Let a deep, noble blue be a quiet accent to your days.
May its dignified color stay softly by your side.
- Is that natural stone real? — Identification & the truth about treatments
- A ¥3,000 vs ¥8,000 earring — where the difference lies
- Plating guide — rhodium, 18K, 14K white gold & vermeil
- Jewelry gift guide — by price and occasion
- The choice of silver 925 — jewelry that lives with nature
- Natural stone jewelry guide — knowing material & meaning
- Metal allergy & jewelry materials — a correct-knowledge guide
