Diamond, the most famed and fabled of all gemstones, is very unique in many ways. Renowned for being the hardest substance on earth, its sparkling fire, durability, and rarity make Diamond the most prized of all gems. No gemstone contains as much allure and interest as does the Diamond. Most Diamonds used as gemstones are colorless or very faintly colored. However, colored Diamonds, known as “fancies”, can be extremely rare and valuable, and the most valuable gemstones ever known have been fancy Diamonds.