Because it symbolises fidelity, the sapphire is often chosen as an engagement ring. Prince Charles gave Lady Diana Spencer a sapphire and diamond pompadour ring for their engagement, which is now worn by Kate, the current Princess of Wales and future Queen of England.

We continue with the royal family of England and Eugenie of York, who received a magnificent 2-carat padparadscha sapphire, or "the colour of a lotus flower at sunset", as her engagement ring.

Beyond the symbolism, do you know the 5 main advantages of sapphire ?

1: Sapphire is one of the 4 so-called precious stones.

Sapphire belongs to the very exclusive club of precious stones, which has only four members: diamonds, rubies, emeralds and sapphires. It is an aluminium oxide coloured by titanium (which gives it its blue colour) and by iron (which darkens the gem to a greater or lesser extent depending on its iron content).

2: Sapphire is extremely hard

Sapphire is the most scratch-resistant gemstone after diamond, with a hardness of 9 on the Mohs scale. So choosing a sapphire as an engagement ring central stone is a wise and rather reassuring choice, as the bride-to-be will be wearing her ring every day.

3 : The sapphire adapts to all types of mountings

White gold, rose gold, yellow gold, platinum, with or without diamonds, the sapphire will be the centrepiece of your engagement ring: a pompadour ring with an oval sapphire, a daisy ring with a round sapphire or a solitaire ring with a cushion-cut sapphire surrounded by triangular diamonds.

4: Sapphire comes in all the colours of the rainbow

Best known for its blue colour, did you know that sapphires come in purple, mauve, pink, orange, yellow, green, black, white or even colourless? This range of colours is sure to please many engaged couples, especially those of you looking for a little originality.

- Blue is the best-known shade of sapphire and one of the most expensive.

- The orange-pink colour is known as Padparadscha, from the Sinhalese padam radshen "lotus flower", which was the first expression used to describe the colour of this very special sapphire. The hue oscillates between pink and orange sapphires, ranging from light to dark. It's a very rare colour, highly prized and very expensive.

- It is iron that gives sapphire its yellow or orange hue. Its purity makes it an alternative to the much more expensive yellow diamond.

- Pink sapphire is actually a lightly tinted ruby. Like ruby, it is a corundum that contains chromium. When the amount of chromium is reduced, the ruby becomes a pink sapphire. Pink sapphires often replace pink diamonds because they are much more affordable.

- Green sapphire, very fashionable recently and much sought-after in blue/green tones. It is the least known of the sapphires. Like yellow sapphire, it owes its colour to the presence of iron oxide. More resistant and less expensive, it is sometimes chosen instead of emerald.

5: Sapphire can be less expensive than its 3 other "precious" cousins

Ruby, diamond and emerald. The price of a "precious" stone depends above all on its colour, size, purity and weight (in carats).

In the case of sapphire, another criterion comes into play: whether or not the stone has been heated (for more information on this subject, see "Why opt for an unheated sapphire"). Sapphire prices vary according to the colour of the stone, with blue and Padparadscha being the most expensive, followed by yellow sapphires, pink sapphires, orange sapphires and green sapphires.

Coloured sapphires, even when unheated, are still affordable and are an excellent alternative to blue sapphires.

Don't forget that colour is the most important criterion for determining the quality of a stone.

If you are interested in sapphires engagement rings, don’t hesitate to discover what Les Pierres de Julie offer in our store…

We are also available for any free expertise of your sapphire jewelry, for that you can send an email with your photos to contact@lespierresdejulie.com.

Whether you're interested in buying a piece of jewellery or a stone, a free jewelry appraisal or jewelry resale, Pierres de Julie welcomes you to its Parisian boutique in the Village Suisse, a stone's throw from the Ecole Militaire and the Esplanade des Invalides.