Different Sizes of Diamond Formation in Natural Processes

摘要

On the basis of geological and astrophysical data, it is possible to distinguish three different mechanisms of diamond formations of different sizes. The first one is the formation of macrodiamonds in the upper mantle rocks formed at high pressures and temperatures. The second one is micron-sized diamond formation in rocks of the Earth's crust formed at P-T parameters corresponding to graphite stability. The third one is nanodiamond (less than 100 nm) formation at 300-500 degrees C and low pressures from organic matter in space. On the basis of theoretical and experimental data, it is possible to conclude that the different sizes of diamonds could have been formed in a wide range of pressures and temperatures in natural processes and their size is connected with the P-T parameters.