Which rock is the main host rock for many diamond deposits?

Kimberlite is the main host rock for many primary diamond deposits.

Kimberlite is a volatile-rich igneous rock that rises rapidly from deep within Earth. Its magma can transport diamonds from the mantle to the surface before they dissolve or transform. Kimberlite pipes are narrow, carrot-shaped volcanic bodies formed when this material erupts or intrudes explosively.

The rock is named after Kimberley in South Africa, where major diamond discoveries in the late nineteenth century helped establish the scientific and mining importance of kimberlite. Not every kimberlite contains diamonds, and even diamond-bearing bodies may be uneconomic to mine.

Diamonds can also reach the surface in unusual rocks called lamproites, so kimberlite is not the only possible host. Diamond prospecting therefore uses geology, indicator minerals, geophysical data, and sampling rather than assuming that every volcanic pipe is productive.