de Bruin, D. 1995. Clinopyroxene megacrysts from the Kalkput kimberlite: A group 2 kimberlite from the Prieska group of kimberlites. International Kimberlite Conference: Extended Abstracts. 6, 1 (Sep. 1995), 71–73. DOI:https://doi.org/10.29173/ikc1785.