Ruby

For thousands of years, the ruby has been considered one of the most valuable gemstones on Earth. It has everything a precious stone should have: magnificent colour, excellent hardness and outstanding brilliance. In addition to that, it is an extremely rare gemstone, especially in its finer qualities.

Ruby is the red variety of the mineral corundum, one of the hardest minerals on Earth, of which the sapphire is also a variety. Pure corundum is colourless. Slight traces of elements such as chrome, iron, titanium or vanadium are responsible for the colour. These gemstones have excellent hardness. On the Mohs scale their score of 9 is second only to that of the diamond. Only red corundum is entitled to be called ruby, all other colours being classified as sapphires.

Colour is a ruby's most important feature. Its transparency is only of secondary importance. So inclusions do not impair the quality of a ruby unless they decrease the transparency of the stone or are located right in the centre of its table. On the contrary: inclusions within a ruby could be said to be its 'fingerprint', a statement of its individuality and, at the same time, proof of its genuineness and natural origin. The cut is essential: only a perfect cut will underline the beauty of this valuable and precious stone in a way befitting the 'king of the gemstones'. However, a really perfect ruby is as rare as perfect love. If you do come across it, it will cost a small fortune. But when you have found 'your' ruby, don't hesitate: hang on to it!

Information by : http://www.gemstone.org