I have a couple questions regarding the transformation of graphite to diamond. As I understand a common method of diamond synthesis involves applying high pressure and high temperature to a graphite sample for a few days and then removing the high temperature and finally the high pressure to insure the carbon takes the diamond form and maintains it at S.T.P. According the the carbon phase diagram http://dao.mit.edu/8.231/carbon_phase_diagram.jpg" it is obvious that the introduction of high temperature reduces the necessary high pressure needed to create diamond. Questions. Could diamond be formed without the introduction of high temperature as long as the applied pressure is above the required pressure according to the phase diagram? And would it stay in the diamond phase once the pressure is released? Does high pressure alone have the capacity to heat up the graphite sample, and if so how is this change in temperature calculated? Is the time required to make diamond related to the pressure applied, would higher pressures allow for large diamonds to be made more rapidly?