Nick Sobolev is a world-wide distinguished scientist whose work on the petrology, mineralogy, and geochemistry of high-pressure (HP) and ultrahigh-pressure (UHP) crustal and mantle rocks, kimberlites, as well as their xenoliths and diamonds, has had a profound effect on many disciplines in Earth science. He was one of the early pioneers in the study of the morphology and composition of mineral inclusions in diamonds, with a focus on Siberian and Uralian samples, and his 1974 book on “Deep-Seated Inclusions in Kimberlites and the Problem of the Composition of the Upper Mantle” (translated into English by the Geophysical Lab in Washington, D.C. and printed by the American Geophysical Union in 1977) rapidly became not only the world-wide “Bible of Yakutian Kimberlites”, but the most thorough collection and scientific evaluation of mantle mineralogy for decades. Many of the principles in this book were only later recognized for their value in diamond exploration.