Most natural diamonds are formed at high temperature conditions existing at depths of 140 to 190 kms(87 to 120 miles) in the earth mantle(inside earth).Carbon containing minerals provide the carbon source,and the growth occurs from 1 billion to 3.3 billion years that is approximately(25 - 75 % of the age of the earth.)
Diamonds are brought close to the earth's surface through deep volcanic eruptions by a magma,which cools into igneous rocks known as Kimberlites and Lamproites(Raw diamonds).
Artificial Diamond
Diamonds can also be produced synthetically in a high pressure and high temperature this process simulates the process which happens in the earth's mantle.An alternative and completely different technique is Chemical Vapor Deposition(CVD) The outcome is called as diamond simulant.It resembles diamond in appearance and many properties as well.
