Where are diamonds most commonly found in the world?
Diamond
{'answer_start': array([606]), 'answer_text': array(['Popigai crater'], dtype=object)}
Most diamonds come from the Earth's mantle, and most of this section discusses those diamonds. However, there are other sources. Some blocks of the crust, or terranes, have been buried deep enough as the crust thickened so they experienced ultra-high-pressure metamorphism. These have evenly distributed microdiamonds that show no sign of transport by magma. In addition, when meteorites strike the ground, the shock wave can produce high enough temperatures and pressures for microdiamonds and nanodiamonds to form.[47] Impact-type microdiamonds can be used as an indicator of ancient impact craters.[48] Popigai crater in Russia may have the world's largest diamond deposit, estimated at trillions of carats, and formed by an asteroid impact.[49]