Experiments and the high density of diamonds tell us that they crystallize at very high pressures. In nature this means that diamonds are created by geologic processes at great depth within Earth, generally more than 150 kilometers down, in a region beneath the crust known as the mantle. Other processes bring diamonds to where people can find them.
The three concentric layers of the Earth -- the core, mantle, and crust -- formed within a few hundred million years of Earth's coalescence 4.5 billion years ago. The core makes up a large fraction of the mass of Earth. The mantle is between the core and the thin crust and is composed of magnesium and iron silicate minerals. Diamonds can form in most of Earth's interior but not near its surface, where graphite is the stable form of carbon. Diamonds only survive at Earth's surface because great heat is required to break down the diamond structure.
So, if diamonds form in the ancient mantle, how do you explain how long this process takes?
2006-10-09
14:53:52
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13 answers
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asked by
AuroraDawn
7