The combination of extreme hardness and optical luster makes diamonds almost flawless as gemstones. Because of their hardness, virtually nothing can scratch them, and so they keep their perfectly faceted shape and pristine sparkle not just throughout the lifetime of the wearer but throughout the lifetime of a civilization—through rain or shine, whether worn in a sandstorm, hacking through a jungle, or just doing the washing up. Even in antiquity diamond was known to be the hardest material in the world. The word diamond is derived from the Greek adamas, meaning “unalterable” or “unbreakable.”
