Diamonds are made of the element carbon. They form under high-pressure and high-temperature conditions deep within the Earth's mantle, where carbon atoms bond in a crystal lattice structure, giving diamonds their remarkable strength and brilliant clarity. This unique arrangement of atoms contributes to diamonds being one of the hardest natural substances known. Diamonds have a variety of uses, from industrial applications such as cutting tools to being highly coveted gemstones in jewelry. Their beauty, rarity, and durability make them highly valued in various cultures worldwide.