Diamond is made from the chemical element carbon. In a diamond, carbon atoms are arranged in a crystal lattice structure, which gives it its exceptional hardness and brilliance. Diamonds are formed under extreme heat and pressure deep within the Earth over millions of years. This unique arrangement of atoms not only contributes to their stunning optical properties but also makes diamonds one of the hardest natural substances known. Carbon, in various forms, exists in many places, but the specific conditions required to create diamonds are rare, making them highly valued gemstones in jewelry and various industrial applications.