All you need to know about blue sapphire

Prestigious origins

Le sapphire belongs to the corundum family, like ruby. Its blue colour is due to the presence of titanium and iron in its chemical composition. Since ancient times, sapphire has been associated with royalty, loyalty and wisdom. A symbol of truth and purity, it is often chosen for engagement rings or wedding jewellery.

The most famous deposits are in Kashmir, Sri Lanka (Ceylon), Madagascar and Thailand. The Kashmir sapphirewith its incomparable velvety blue, remains the most sought-after in the world.

How do you value a blue sapphire? The essential criteria

As with diamonds, the quality of a blue sapphire depends on several criteria:

• The colour Colour: this is the most important factor. We're looking for an intense hue, neither too dark nor too light, with high saturation and excellent colour distribution.

• Clarity A natural sapphire often has small inclusions. A perfectly clear sapphire is rare and highly prized. However, some typical inclusions may indicate a geographical origin.

• The cut A well-proportioned cut reveals the stone's full potential. Sapphire is often cut in oval, cushion or round shapes to maximise its brilliance.

• Weight (carat) The larger the stone, the more precious it is, especially if its colour and clarity are exceptional.

Treat yourself to a blue sapphire

As well as its beauty, the blue sapphire offers powerful symbolism. It embodies fidelity, inner peace and protection. It is also one of the hardest stones after diamonds (9 on the Mohs scale), making it an excellent choice for everyday jewellery.

Many top jewellery houses, including Cartier, Chaumet and Boucheron, use it in their iconic creations. Lady Diana's engagement ring (now worn by Kate Middleton), set with a Ceylon blue sapphire, remains the most famous example of the link between this stone and history.

Please note that the majority of blue sapphires on the market are heatedThis is a common and accepted treatment that improves colour and clarity. This treatment must always be mentioned. On the other hand, sapphires unheated are much rarer and more sought-after, as their colour is a natural 100 %. For a secure purchase, we recommend that you ask for a gemmological certificate issued by a recognised laboratory (GIA, SSEF, AGL, etc.), especially for stones of a certain value.

The market for second-hand jewellery is brimming with vintage or signed blue sapphires, often mounted on one-off pieces. Buying second-hand jewellery not only gives you access to exceptional stones at a more affordable price, but also makes you part of a sustainable approach.