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Where are natural diamonds found and what is kimberlite?

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A labeled diagram of the periodic table entry for carbon, showing its atomic number 6, symbol C, electron configuration, atomic weight range, solid physical state, hexagonal crystal structure, and weakly acidic oxide properties. Color coding and icons indicate it is a nonmetal, solid at room temperature, with hexagonal structure and weak acidity. — carbon Carbon and its properties.

Natural diamonds are formed deep within the Earth's mantle, where extreme heat and pressure allow carbon atoms to bond into a crystal structure. These diamonds are transported toward the surface by powerful volcanic eruptions and are typically found in kimberlite pipes, as well as in alluvial gravels and glacial tills.1

What is Kimberlite?

Kimberlite is a dark-colored, intrusive igneous rock that often contains diamonds within its matrix. It is a type of mica peridotite characterized by a porphyritic texture, featuring large crystals surrounded by a fine-grained groundmass.2

These rocks originate in the asthenosphere and rise through the lithosphere via fissures, forming vertical, funnel-shaped pipes. As the magma ascends, it may pass through the "diamond stability field," where it can collect diamonds and carry them to the surface. Notable locations for these deposits include South Africa, Botswana, Australia, and Tanzania.234