Are white sapphires rare and valuable

However natural white sapphires are becoming rare and, therefore, more valuable in the market place, because they're increasingly manufactured into 'blue' sapphires at source.

Q. What determines the colour of a sapphire

A. Although most people think of sapphires as being exclusively blue, these precious stones come in a variety of colours. All colours of corundum except red (ruby) are considered to be sapphire.

Sapphires are made of corundum, a hard mineral of aluminium oxides. Different colours are formed due to different impurities found in the corundum. Blue sapphire gets its colour from titanium and iron oxides.

Q. What makes white sapphires white

A. White Sapphires are formed of pure corundum, without any impurities and, therefore, they're actually colourless.

The manufacturing process that turns white sapphires into blue ones involves introducing titanium and iron oxides.

Q. Where are white sapphires found

A. In Sri Lanka. They are almost as hard and durable as diamond.

To read more about diamond, click here.

Q. Where does the name sapphire come from

A. From the Latin word 'sapphirus' , which means blue.

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by Lisa Cardy