Mineralogy of Kimberlites

Abstract

The petrography of kimberlite indicates that it is a hybrid rock consisting of fragments of rocks of upper mantle and deep crustal origin intermixed with the crystallization products of a highly volatile fluid. Some of these deep-seated rock crystals are still sufficiently fresh that they are recognizable as having been derived from a particular rock-type, whereas others may have become completely altered by interaction with the kimberlite liquid to form new mineral species. When, to this original mixture, there may be added, particularly in the case of diatremefacies kimberlites, (a) minerals incorporated from the high-level formations forming the wall rocks of the kimberlite intrusions, and (b) later minerals formed during weathering or percolation of groundwater, it will be appreciated that the mineralogy of individual kimberlites may be extremely variable and complex.