WHAT IS DIAMOND?
The word "Diamond" comes from the Greek word "Adama’s", which means indestructible. It is the only gem known to man that is made of a single element, Carbon, besides graphite. Diamond is completely made of Carbon atoms (Chemical Composition - 'C') crystallized in a cubic (isometric) arrangement.
Diamonds form between 120-200 kms or 75-120 miles below the earth's surface. According to geologists the first delivery of diamonds was somewhere around 2.5 billion years ago and the most recent was 45 million years ago. That is a long time, my friend! According to science , the carbon that makes diamonds, comes from the melting of pre-existing rocks in the Earth's upper mantle. There is an abundance of carbon atoms in the mantle. Temperature changes in the upper mantle forces the carbon atoms to go deeper where it melts and finally becomes new rock, when the temperature reduces. If other conditions like pressure and chemistry is right then the carbon atoms in the melting crustal rock bond to build diamond crystals.

There is no guarantee that these carbon atoms will turn into diamonds. If the temperature rises or the pressure drops then the diamond crystals may melt partially or totally dissolve. Even if they do form, it takes thousands of years for those diamonds to come anywhere near the surface.

HOW DIAMONDS COME TO THE SURFACE?
Diamond deposits are called kimberlite pipes, they are also called primary diamond deposits or primary mines. The diamonds found at the river beds are known as ALLUVIAL DEPOSITS.

The original nature take millions of years to make a diamond. A diamond comes from the bosom of the earth. All diamonds are mined are not used for the jewellery. Only 1/4th is mined and made into jewellery. Every 100 tones of mud produces one carat of a diamond. This one carat varies anything from 0.005ct to 1ct.