In earlier times, some people believed that the firmament was an enormous blue sapphire in which the Earth was embedded. Could there be a more apt image to describe the beauty of a sapphire? And yet this gem comes not in one but in all the blue shades of that firmament, from the deep blue of the evening sky to the shining mid-blue of a lovely summer's day which casts its spell over us. However, this magnificent gemstone also comes in many other colors: not only in the transparent grayish-blue of a distant horizon but also in the gloriously colorful play of light in a sunset – in yellow, pink, orange and purple. Sapphires really are gems of the sky, although they are found in the hard ground of our 'blue planet'.

Blue is the main color of the sapphire. Blue is also the favorite color of some 50 per cent of all people, men and women alike. We associate this color, strongly linked to the sapphire as it is, with feelings of sympathy and harmony, friendship and loyalty: feelings which belong to qualities that prove their worth in the long term – feelings in which it is not so much effervescent passion that is to the fore, but rather composure, mutual understanding and indestructible trust. Thus the blue of the sapphire has become a color which fits in with everything that is constant and reliable. That is one of the reasons why women in many countries wish for a sapphire ring on their engagement. The sapphire symbolizes loyalty, but at the same time it gives expression to people's love and longing. Perhaps the most famous example of this blue is to be found in music, in George Gershwin's "Rhapsody in Blue". And the blue of the sapphire even appears where nothing at all counts except clear-sightedness and concentrated mental effort. The first computer which succeeded in defeating a world chess champion bore the remarkable name 'Deep Blue'.