Natural Coloured Diamond

Diamond, is formed at around 150 kilometers within the Earth's mantle, just above the Earth's molten core.  Under intense heat & pressure, carbon molecules are crystallized to become these brilliant little stones, the hardest substance on Earth.  In rare occasion, a pipelike vent opens at the superhot molten material just underneath the mantle which causes a crack at the base of mantle.  The pipelike vent allows molten flow to shoot upward, under volcanic-like pressure.  Along it, surrounding material containing the formed diamonds are carried to surface of Earth.  These pipelike elevators are called "Kimberlite" and "Lamproite".

These occasions only happen very rarely.  When all the conditions are perfect, it only takes a few days for carbon atoms to be transformed into rough diamond structures.  However, it may take millions, or even billions of years before diamonds are formed and can surface on Earth to be discovered. 

For natural color diamonds to be formed, in addition to the physical conditions necessary for forming diamond, trace elements interaction or radiation must also occur in the diamond crystal formation, making natural color diamonds extremely rare.  Only one out of 10,000 diamonds made the trip to the Earth’s surface is naturally colored.  Therefore, natural color diamond is truly one of a kind, and it is the world's most concentrated form of wealth.

Nitrogen imparts yellow or orange shades to a diamond.  Boron imparts blue shade to a diamond ranging from deep blue to sky blue.  Hydrogen produces unique violet hues.  Tremendous pressure which abnormally compresses diamond's structure creates a red, pink, purple or brown stone.  In many Argyle pink & cognac diamonds, evidence of graining can be seen at 10x magnification.  Scientists believe it attributes to the tremendous pressures under the earth. 
   
Whereas natural radiation impacting already formed diamonds over millions of years can give them a green hue.