Diamond in kimberlite from the Cretaceous of South Africa. (Seaman Mineral Museum collection, Houghton, Michigan, USA)

Kimberlites and lamproites have significant 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 Siberia, 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 an idealized cross-section in the shape of a martini glass.

The kimberlite sample seen here, with a diamond in matrix, is from a diamondiferous pipe at Kimberley. Weathered kimberlite has been nicknamed "yellowground". Unweathered kimberlite, like this rock specimen, has been nicknamed "blueground".