Mantle Rocks and Diamond-Associated Phases: Role in Diamond Origin

The components of rock-forming and accessory minerals of the upper mantle, transition zone and lower mantle rocks have been involved into the processes of diamond genesis. Through their dissolving in primary carbonate melts, the mantle minerals have turned into components of the parental silicate-(±oxide)carbonate-carbon melts-solutions for diamonds and co-crystallized paragenetic minerals. The minerals newly crystallized from the melts-solutions have been fragmentarily included into diamonds commonly growing with them. Xenogenetic accessory solid and liquid phases of the mantle rocks easily penetrating into the low-viscous diamond-parental melts can also be trapped by the growing diamonds. So, the mantle petrological processes are marked by the diamond-forming episodes that is of significant importance for solution of the diamond genesis problem. Therewith, the crucial information is directly related to the origin of primary mineral inclusions in natural diamonds of the deep Earth’s interiors. Realization of new lines of attack to the problem of genesis of not numerous diamond-bearing peridotites and eclogites, which were discovered together with the upper-mantle diamond-free xenoliths in kimberlites, has been made possible in the context of the mantle-carbonatite conception of genesis of diamonds and associated phases. All the above will allow an understanding of the role of minerals and rocks associated with diamonds in resolution of the principal problems of the genetic mineralogy of diamond. In the current comprehension, genesis of diamonds and associated phases have been proceeded within the detached reservoirs-chambers of diamond-parental melts inside of the enclosing them upper mantle, transition zone and lower mantle rocks.