The mineral commonly associated with diamonds is carbon. Diamonds are a crystalline form of carbon and are formed under high pressure and temperature deep within the Earth's mantle. The unique arrangement of carbon atoms in a diamond structure gives it exceptional hardness and brilliance. While carbon is the primary component of diamonds, they may also contain trace elements and impurities, which can affect their color and clarity. Other minerals, such as graphite, are also forms of carbon, but unlike diamonds, they have different crystal structures and properties, illustrating the versatility of carbon in its various forms.