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Blue Sapphire Guide

Buying tips, facts & history



our source

Our Source

mineral class

Mineral class


9 Mohs Scale

birthstone month

Birthstone month

wedding anniversaries

Wedding anniversaries
5th and 45th

blue sapphire facts

Hard Facts

Sapphires are made from the mineral corundum. It exists in a rainbow of colours including pink, yellow, green and grey, but the blue-hued variety is the best known (Red corundum crystals are called rubies).

On the Mohs scale of hardness bluesapphire rates 7.5 – 8. The word “bluesapphire” comes from the Latin words “aqua” and “mare”, meaning “water” and “sea”.

where on earth?

Where on Earth?

We source our sapphires almost exclusively in Thailand.

Sapphires are mined in about twenty different countries – including China, Madagascar and Australia – but Thai sapphires are very sought after because of their high quality.

Thailand has a generations-long tradition in sapphire mining and cutting. This has led to modern, ethical mining practices and the production of high grade gemstones.

september birthstone

Birthstone and Anniversary

Sapphire is the September birthstone. It is also gifted on 5th and 45th wedding anniversaries.

Blue sapphire necklaces and rings make beautiful early autumn birthday and bridal presents. They are said to bring luck, loyalty and happiness in love. The sapphire’s symbolism and durability also makes it ideal for engagement rings.

blue sapphire buying guide

Buying Guide

How to assess a Blue Sapphire’s quality and value?

Our gem expert determines a blue sapphire’s worth in a way very much like diamonds. Clarity is the foremost consideration, and then colour, cut and carat weight.

Sapphire is one of the “Big Three” gemstones of the world, the others being ruby and emerald. This makes sapphire jewellery extremely popular.

However, not all gems have the same quality and it’s good to know what you’re looking for before you buy.

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A blue sapphire’s primary hue, or colour, is simply blue. However, blue sapphires are natural gemstones, so their tones can vary from very light to intense dark blue. This variation can happen even within one stone (it is called “colour zoning”). The expert’s trick is to look for vivid saturation of colour combined with good clarity, rather than a specific hue.

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Blue sapphires with a combination of perfect clarity and intense colour saturation are extremely rare. Large sapphires are therefore much more expensive than small sapphires of the same quality. The blue sapphire on Catherine Middleton’s ring weighs 12 carats. But typical sapphire jewellery sold on the high street tends to go only up to about 5 carats. That way it remains affordable for all budgets.

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Much emphasis is placed on a sapphire’s colour, but when it comes to jewellery you should check clarity first. Commercially used sapphires typically have some natural inclusions, because completely clear gems are simply too rare and expensive. Our gemmologist therefore recommends you look for sapphires that have minimal imperfections, yet allow lots of light to pass through them. This way your sapphire jewellery will have lots of sparkle.

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A superlative sapphire cut will flatter a stone’s colour, adjust any colour zoning, and bring out natural glimmer. An ingenious cut will also minimise the appearance of any small inclusions, something that is accepted as a part of commercial sapphire jewellery. Because of the shape of its crystal, cut sapphires may appear “deeper” than other gemstones of the same size.

natural or treated blue sapphires

Natural or Treated?

Some stores sell sapphires that are heat treated or fracture-filled to intensify their colour or hide inclusions. However, our gem expert would always recommend buying natural sapphires.

Even if your sapphire appears to have tiny lines, this should not be considered a defect. Small inclusions are a good sign that your gemstone is natural and untreated and form part of the sapphires million-year-old makeup.

blue sapphire care

Care and Cleaning

Sapphires are very durable gems. However, they are natural, precious stones that should be treated with care. This means you should not scrub them harshly or exert excessive pressure when cleaning.

The safest and cheapest way to clean your sapphire jewellery is with warm water and mild soap, scrubbing gently with an old toothbrush. Use a bowl rather than a sink, so there’s no risk of your gems falling down the drain. Afterwards, pat them dry with a lint-free towel or leave to air-dry on a clean cloth.

modern history

Modern History

Today, blue sapphires are considered to represent loyalty, truth and honesty. They are also closely associated with royalty: blue sapphires feature in several countries’ crown jewel collections, in particular Holland and the United Kingdom.

The most famous blue sapphire of our time is the one on the Duchess of Cambridge’s engagement ring. Find out more about this beautiful piece of jewellery below, under Famous Sapphires.

famous blue sapphires

Famous Blue Sapphires

Right now the most famous blue sapphire in the world is the one Prince William gave to Catherine Middleton for their royal engagement in 2010. The ring originally belonged to his mother, Princess Diana. It is now considered a royal heirloom, valued at more than £300,000. The ring’s blue sapphire weighs a staggering 12 carats and is cut into an oval shape. It is set in 18K white gold and surrounded by diamonds.

legend and myth

Legend & Lore

In old Persian lore, the Earth was said to be balanced on top of an enormous sapphire and its reflection gave the sky its blue colour.

The ancient Greeks and Romans also claimed blue sapphires held mystical powers, giving their owners wisdom and health. In the Middle Ages, blue sapphires were often worn by royalty as amulets to ward off evil.