Where do the world’s biggest diamonds come from? Geology now has answers

Some of the most extraordinary gems ever found belong to a rare class of diamonds known as CLIPPIRs (Cullinan-like, Large, Inclusion-Poor, Pure, Irregular, Resorbed). They make up less than 1% of all diamonds on Earth, and include three of the largest diamonds ever recovered, the Cullinan, at 3,106 carats, found at the Premier mine in South Africa; the 1,111 ct Lesedi La Rona, discovered at the Karowe mine in Botswana in 2015 and sold for US$53 million in 2017; and the 2,492 ct Motswedi…