'n Voorbeeld van Bellsbank-Kimberliet uit Kryttydse gesteentes te Mount Rupert, Noord-Kaap. Hierdie diamantdraende gesteente het 118 miljoen jaar gelede die Proterosoïese dolomietgesteente van die Ghaap-groep deurdring.
Afrikaans: Spesimen (6,6 cm breed tussen wydste punte) van Bellsbank-Kimberliet uit Kryttydse gesteentes in Suid-Afrika. Kimberliete en lamproïete is van geweldige ekonomiese belang omdat hulle gasheergesteentes vir edelsteen- en nywerheidsgraad-diamante is. Hulle is ongewone stollingsliggame met, in geheel, pypvormige geometrieë. Hul vormingsmetode word net deels begryp ​​omdat daar geen eietydse waarneming van hul vorming is nie. Die twee gesteentes is van verspreide gebiede oor die hele wêreld bekend, maar slegs sommige daarvan is beduidend diamantdraend. Indië en Brasilië is klassieke vindoorde vir diamante. Daar is ook bevind dat Afrika baie kimberliet het en die kontinent is wêreldbekend vir die produksie van groot hoeveelhede diamante. Ander gebiede met noemenswaardige voorkoms van diamantdraende kimberliet of lamproïet is in Rusland, China, die noordweste van Australië en die noordweste van Kanada geleë. Kimberliete is vernoem na Kimberley in die Noord-Kaap, Suid-Afrika, en verskeie kimberlietpype is hier te vinde. Kimberliete toon met toenemende diepte 'n geleidelik-vernouende, pypvormige dwarssnit. Lamproïete weer toon 'n dwarssnit wat aan 'n martini-glas herinner. Bo is 'n voorbeeld van Suid-Afrika se diamantlewerende Bellsbank-Kimberliet, wat ook die tipiese voorkoms van kimberliet voorstel, naamlik 'n mengelmoes van kristalle en klastiese gesteente. Vuilgroen-gekleurde, geserpentiniseerde en deels geserpentiniseerde oliviene met donker groengrys reaksierande is algemeen en opvallend. Verspreide flogopitiese mika en granaat is ook teenwoordig. Die Bellsbank-Kimberliet het tydens die latere vroeë-Kryt (Aptium-tydsnede, 118 Mj gelede) deur Proterosoïes-daterende dolomietgesteente van die Ghaap-groep gedring. Ligging: Bellsbank-myn naby Mount Rupert benoorde van Kimberley in die Noord-Kaap, Suid-Afrika. English: Bellsbank Kimberlite from the Cretaceous of South Africa (6.6 cm across at its widest). Kimberlites and lamproites have tremendous economic importance because they are host rocks for gem-grade and industrial-grade diamonds. Kimberlites & lamproites are unusual igneous bodies having overall pipe-shaped geometries. Their mode of formation is only moderately understood because they have not been observed forming. Kimberlites & lamproites are known from scattered localities throughout the world - only some are significantly diamondiferous. Classic localities for diamonds are India and Brazil. Africa was also discovered to have many kimberlites and is world-famous for producing large numbers of diamonds. Other notable diamondiferous kimberlite-lamproite occurrences include Russia, China, northwestern Australia, and northwestern Canada. Kimberlites are named for the town of Kimberley, South Africa. Several kimberlite pipes occur in the Kimberley area. Kimberlites have a gently tapering-downward, pipe-shaped cross-section. Lamproites have a cross-section more closely resembling that of a martini glass. Here’s a sample from South Africa’s diamondiferous Bellsbank Kimberlite. It has the typical appearance of a kimberlite: a jumbled mix of crystals and clasts. Dirty green-colored, serpentinized & partially serpentinized olivines with dark greenish-gray reaction rims are common and conspicuous. Scattered phlogopite mica and garnet are also present. The Bellsbank Kimberlite intruded through Proterozoic-aged dolostones of the Ghaap Group during the late Early Cretaceous (Aptian Stage, 118 Ma). Locality: Bellsbank Mines, near Mount Rupert, north of Kimberley, north-central South Africa