Crystallization of diamond from a silicate melt of kimberlite composition in high-pressure and high-temperature experiments

In high-pressure and high-temperature experiments (1800- 2200 °C and 7.0-7.7 GPa), diamond crystallized and grew in a volatile-rich silicate melt of kimberlite composition. This diamond has well- developed {111} faces, and its morphologic characteristics resemble those of natural diamond but differ from those of synthetic diamond grown from metallic solvent-catalysts. The kimberlite melt has a strong solvent-catalytic effect on diamond formation, supporting the view that some natural diamonds crystallized from volatile-rich melts in the upper mantle.