Diamant

Diamant is a natural solid form of carbon that crystallizes in a tetrahedral lattice of sp3-bonded atoms. It is renowned for its extreme hardness, ranking 10 on the Mohs scale, and for a high refractive index and dispersion that give it notable brilliance when cut as a gemstone. While most diamonds are valued for jewelry, a substantial portion is used industrially for cutting, grinding, and drilling due to their hardness and thermal conductivity.

Natural diamonds form deep within the Earth’s mantle under high pressure, typically at depths of about 140 to 190 kilometers. They are transported to the surface by deep-source volcanic eruptions that create kimberlite pipes. Radiometric dating indicates many diamonds are billions of years old. Major sources include Russia, Botswana, Canada, Australia, the Democratic Republic of the Congo, and Angola, among others.

Gem-quality diamonds are evaluated using the 4 Cs: carat, color, clarity, and cut. Carat measures weight; color ranges from colorless to various hues; clarity describes internal and surface features; cut relates to the gem’s proportions and brilliance. For industrial diamonds, color and clarity are less critical, and the emphasis is on crystal quality and size.

Synthetic diamonds are produced in laboratories through high-pressure high-temperature (HPHT) methods or chemical vapor deposition (CVD). Lab-grown diamonds have the same crystal structure and most physical properties as natural diamonds and are increasingly used in jewelry, as well as in machining, optics, and electronics.