Kimberlite contains what precious item

Kimberlite is an igneous rock best known for sometimes containing diamonds.

It is named after the town of Kimberley in South Africa, where the discovery of an 83.5-carat (16.70 g) diamond called the Star of South Africa in 1869 spawned a diamond rush, eventually creating the Big Hole.

Read more...https://en.wikipedia.org/wiki/Kimberlite

Books
Kimberlites, Diatremes, and Diamonds: Their Geology, Petrology, and Geochemistry (Special Publications): Henry O. A. Meyer, F. R. Boyd: 9780875902128: Amazon.com: Books http://tipsandsteps.com/shortlink/ak