An ultramafic igneous rock containing at least 35% olivine, with one or more of the following in the groundmass; monticellite, phlogopite, carbonate, serpentine, diopside. No leucite is allowed in the definition of kimberlite (Woolley et al., 1966). The name, proposed by Lewis in 1888, is for the Kimberley district, South Africa, where kimberlite is a host for diamonds. Two types of kimberlite have long been distinguished. Basaltic kimberlite or Type 1 kimberlite is much the more widespread, and constitutes the classic diatreme-filling diamond-bearing rocks of South Africa. Micaceous kimberlite, also called lamprophyric kimberlite or Type 2 kimberlite, is apparently restricted to southern Africa, and differs so strongly from Type 1 that some authorities do not consider it a variety of kimberlite (Mitchell, 1986).
Mitchell, R.H. (1986): Kimberlites: Mineralogy, Geochemistry, and Petrology. Plenum Press, New York, 441 p.
Source: AGI Glossary of Geology, 4th edition, 1997
Geological keywords, such as “granite”, “lake”. The definitions are generally taken from the AGI Glossary of Geology. Keywords with a geographic context (e.g. Cape Smith Fold Belt, Selwyn Basin, Grenville Province) are assigned to a separate category.
- Date modified: