Geophysical conditions are sometimes therefore extreme that quantities neglected in normal laboratory experiments assume overriding importance. For instance, consider the formation of diamond under geophysically typical pressures. The densities of the two allotropes are 2.27g/cm3 (graphite) and 3.52 g/cm3 (diamond) at the temperature of the environment. Explain By how much does U for the transition differ from H in a region where the pressure is 500 kbar?