Geoscientists have always had an interest in how diamonds form. However discussions about diamonds’ origin and their carbon sources are still continue. Many recent studies have shown that carbon isotope data can be helpful in tracing the origin and evolution of diamonds in various geological environments. This book provides results of analyses of diamond-bearing rocks and diamonds from different deposits that have been carried out in order to distinguish the different carbon source for diamonds and their origin. The results should help to confirm the proposal that the source of the carbon in diamonds is the carbonate rocks, minerals and gases which are always present in the rock masses of all known types of diamond deposit. This monograph intended for undergraduate and postgraduate students of mineralogy, petrology and geochemistry and also for research workers in related field.