Kimberlite is a silica-poor, magnesium-rich volcanic rock. Its rare eruptions carry diamonds up from the mantle to Earth's surface.
In more detail
Kimberlite magma forms deep in the mantle as a carbonate-rich melt. It occurs as dikes or pipes; lamproite is a related volcanic rock that also carries diamonds. Many kimberlites contain no diamonds. Most of Earth's kimberlites erupted between 250 and 50 million years ago.
Related terms
- Diamond: Diamond is a single element, carbon, with every atom bonded to four neighbors in a cubic crystal. It is the hardest gem, Mohs 10.
- Natural diamond: A natural diamond is a diamond that formed in the earth, about 160 km deep, under enormous heat and pressure. An eruption carried it to the surface.
- Crystal: A crystal is a mineral crystal contained in a diamond.