Every year, the world consumes more than 10,000 tons of diamond superabrasives, which are indispensable for fields such as construction, metals, ceramics, automobiles, semiconductors, computers, and cellular phones. In fact, the per capita consumption of superabrasives may be used as an indicator of a country's industrial activities. This volume presents several aspects of superhard materials, especially diamond superabrasives and their manufacture, properties, and applications, and introduces several new designs of ultrahard materials that may be harder than diamond. It discusses diamond’s connection with the origin of life, in particular, the origin of the first RNA. In addition, it throws light on the concept of diamond quantum computers with neutrons of the carbon-13 isotope as quantum bits. This innovation may maintain quantum coherence with minimal interference without using complicated cryogenic cooling. Hence, it can be a robust design for future quantum computers. For those interested in the depth of the quantum mechanical world, a chapter elaborates the history of life and humanity in light of the evolution of quantum universes.