A Diamond is a crystalline form of carbon. A diamonds hardness and high dispersion of light makes it particular useful for industrial applications and in jewelery. Diamonds are specifically renowned as a mineral with superlative physical qualities. Thus making them great abrasives because they can only be scratched by other diamonds. This feature also means they hold a polish extremely well and retain luster. Approximately 120 million carats, 25 000 kilograms of diamond are mined annually.