Carbonado typical gem diamonds. Lead isotope analyses have been interpreted as documenting crystallization of carbonados about 3 billion years ago. The carbonados are found in younger sedimentary rocks. Mineral grains included within diamonds have been studied extensively for clues to diamond origin. Some typical diamonds contain inclusions of common mantle minerals such as pyrope and forsterite, but such mantle minerals have not been observed in carbonado. In contrast, some carbonados do contain inclusions of minerals characteristic of the Earth's crust: these inclusions do not necessarily establish formation of the diamonds in the crust, however, because while these obvious crystal inclusions occur
What Is Life During the verses, Gordon moves to a square, Motown-style beat – or "rock-steady Northern soul backbeat" in Leng's words – before returning to the "galloping rhythm" of the more open, "knockout" choruses, and the song is driven equally by Badfinger drummer Mike Gibbins' powerful tambourine work. On "What Is Life", Spector provided what music critic David Fricke terms "echo-drenched theater", in the form of reverb-heavy brass, soaring strings (arranged by John Barham) and "a choir of multitracked Harrisons". The vocals and Barham's contribution, along with a brief slide-guitar commentary from Harrison over the final verse, were overdubbed at Trident Studios,