Mineral Inclusions in Diamond: Temperature and Pressure of Equilibration

Abstract

Two distinct suites of minerals included in natural diamond occur and probably represent different physical and chemical conditions during diamond growth. Minerals of the ultramafic suite appear to have equilibrated in the range 1000° to 1300°C between 45 and 65 kilobars, whereas the temperature range for minerals of the eclogitic suite is 850° to 1250°C. At present, models relating the partitioning of magnesium and iron between coexisting phases are not sufficiently rigorous to determine a value for the pressure of equilibration of these eclogitic suite inclusions.