Published in the April WCGMC Newsletter
Diamonds are found in very unusual magmatic intrusive bodies called kimberlites or in alluvial deposits resulting from the weathering and erosion of kimberlites and the concentration of the hard and resistant gems in placer deposits. Kimberlites are pipe-shaped igneous intrusions that erupted from great depth. With high gaseous and volatile content, they were able to fracture and penetrate the very thick continental crust, often encapsulating blocks of the fractured host rock as they ascended. (Kirkley et. al.,1991). Their pipe-like morphology is evident in the picture of the kimberlite pipe quarry from Kimberly, South Africa pictured in the header of this article.