Diamond is a precious gemstone formed deep within the Earth’s mantle under extreme pressure and temperature over billions of years. Chemically, it is a crystalline form of pure carbon, arranged in a cubic crystal structure that gives diamond its unmatched hardness and high refractive properties. Diamonds exhibit an adamantine luster and a very high refractive index, which results in exceptional brilliance and fire. While most diamonds are colorless or near-colorless, they also occur in a wide range of fancy colors such as yellow, blue, pink, and brown, caused by trace elements or structural distortions during formation. With a Mohs hardness of 10, diamond is the hardest natural material known, making it highly resistant to scratching. However, due to its perfect cleavage in four directions, it can be vulnerable to sharp impacts along specific planes. Diamonds are primarily sourced from countries such as Russia, Botswana, Canada, and South Africa, and are mined from kimberlite and lamproite pipes. In addition to natural diamonds, treated and laboratory-grown diamonds are also available in the market, which are often enhanced for color or clarity using modern techniques like HPHT and irradiation. Beyond jewelry, diamonds play a crucial role in industrial applications, including cutting, drilling, and polishing tools, due to their extreme hardness and thermal conductivity.