Blue sapphire

This beautiful gemstone is one of the best known and most valuable in the world. Together with emerald and ruby, sapphire is often referred to as one of the "big three" of gemstones.

Sapphires are best known for their blue colour. Think of names such as cornflower blue, Ceylon blue and royal blue.

This gemstone is associated with royalty. Think of the world's most famous sapphire ring: Lady Diana's engagement ring, with a 12-carat blue sapphire surrounded by 14 diamonds. Today it is worn by Kate Middleton, Princess of Wales. This classic piece is also a source of inspiration for Celine. Another famous engagement ring with a beautiful blue sapphire belongs to Jennifer Aniston.