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
Now That's What I Call Rock of "Now" features contemporary pop acts with rock roots and takes a "big-tent" approach to the genre. Cliff Chenfeld, co-owner of the Razor & Tie and a consultant for "Now That’s What I Call Rock", feels "most music listeners are pretty open" and this release "is a means of introducing some of those bands to that broader audience who I think would embrace it." The compilers of the set wanted to avoid defining what rock music is in 2016, but instead tried to give what people think it is, "as opposed to using a term for rock that might have