What happens to carbon to form a diamond?

Answer 1

The natural process that formed most diamonds requires that a "collection" of carbon is gradually placed under great pressure and substantial (but not too high) a heat, in the absence of oxygen, for many thousands of years. The site of their formation is within the upper mantle of the Earth, under the continental crust, and the resulting diamonds have ages between 1 and 3.3 billion years.

There are also diamonds formed almost instantaneously by asteroid or meteor impacts, or manmade diamonds formed using very high compression. These "nanorod aggregate diamonds" are harder than normal diamonds, the manmade ones even more so.

There are black diamonds called "carbonado" diamonds that may have formed within supernovas, or may have formed when the already concentrated carbon material impacted on Earth.

Answer 2

The formation of diamonds does not take a long time, it can actually be near to instantaneous (in geological terms). The problem in creating diamonds is to bring the raw material (carbon) into the suitable pressure range where diamond becomes the stable polymorph of carbon. Rocks from the depths where these pressures are achieved are found in areas of very old continental areas (like South Africa). They are known as kimberlites - very rapidly erupting rocks that host the diamonds.

If the ascend of those rocks is to slow, the diamonds convert into graphite on the way as diamond is not stable under surface conditions and when slowly being depressured and cooled the transformation to graphite can take place somewhere in the continental crust. On the surface diamonds do not transform back to graphite because the kinetics of such a transformation are inhibited (its just to cold).

Kimberlites have been dated to be very old (several billion years old) but it did not take the diamonds so long to form (there are even some facilities that can industrially produce diamonds).

Answer 3

Carbon has four available bonds it can make with other atoms. When carbon bonds with itself, it usually bonds with three other carbon atoms making a sheet of carbon atoms, with the fourth bond gliding over the sheet below or above, depending on your perspective.

With a diamond, those sheets are squeezed so hard and under such high temperatures that the sheets molelcularly combine, having the carbon atoms bond to themselves at all four points. This is called diamond.

Answer 4

One miserable night with a bottle of Canadian maple syrup.

Answer 5

It can take thousands of years before carbon becomes a diamond. This process requires a lot of heat and compression.

Answer 6

Carbon turns into diamond through long periods of intense pressure and heat underground. This process could take billions of years.

Answer 7

There is no precise answer, but probably millions of years, the number of millions being what is uncertain.

Answer 8

A diamond already is carbon. A specific crystalline form of carbon.

Answer 9

3 billion years