A lab diamond, also known as a synthetic diamond or a cultured diamond, is a diamond that is created in a laboratory rather than being formed naturally in the Earth's mantle. Like natural diamonds, lab diamonds are made of pure carbon. However, the processes used to create them vary. One method involves subjecting a small diamond "seed" to high pressure and temperature conditions, which causes the carbon to crystalize and form a larger diamond. Another method involves using chemical vapor deposition (CVD) to grow a diamond on a substrate. Lab diamonds have the same physical and chemical properties as natural diamonds and are optically and chemically identical. They are also graded using the same criteria as natural diamonds, including the 4 Cs: carat weight, color, clarity, and cut. Lab diamonds have become an increasingly popular alternative to natural diamonds, as they are often less expensive and are considered more sustainable and ethical