How are Laboratory-Produced Diamonds Created?
Discover the two methods that help you answer the question, “how are lab-grown diamonds made?” CVD and HPHT. Learn how scientists have developed a technique to imitate the natural development of a diamond in a laboratory and how these processes generate genuine synthetic lab diamonds similar to those found in nature.
How are diamonds created in a laboratory?
Laboratory diamonds in a controlled environment replicate how diamonds are formed organically beneath the Earth’s mantle. CVD (chemical vapour deposition) and HPHT (high-pressure high temperature) are the two techniques used to make lab diamonds (high-pressure high temperature). Both produce high-quality, genuine diamonds similar to those found in nature. In a few weeks, the carbon gas ionises, and the particles adhere to the initial diamond slice before crystallising into a formed diamond.
When the HPHT method gets used, a piece of diamond seed gets inserted into a piece of carbon. The carbon is then compressed to roughly 1.5 million pounds per square inch using a belt press, cubic press, or split-sphere (BARS) press. Furthermore, the carbon gets subjected to temps exceeding 2,700 degrees Fahrenheit. The pressure and heat dissolve the carbon to form a diamond around the original diamond seed. After that, the new forms of the diamond get meticulously cooled.
CVD, like HPHT, employs a tiny diamond seed (often an HPHT diamond). This seed is in a sealed chamber heated to over 1,400 degrees Fahrenheit and with carbon-rich gases (typically methane and hydrogen). These molecules get ionised into plasma via a process comparable to lasers or radiation. This technique tears down the gas’s molecular bond. When the molecular link gets disrupted, pure carbon starts to adhere to the seed and forms a new diamond. Additional procedures (heat or irradiation) may get used after the diamond forms to improve or alter its hue.
Plant the germ:
The HPHT procedure starts with a seed crystal, which is a tiny diamond fragment. It is a press chamber with a metal catalyst, such as nickel or iron. On top is a lump of carbon, such as graphite.
Apply some weight:
The compactor raises the temperature of the chamber to a blistering 1,600°C. It then applies pressure with metal anvils. The force and temperature must get sufficiently elevated to dissolve the metal catalyst.
Molten metal transports carbon atoms from graphite to the seed crystal. Carbon atoms gradually accumulate around the crystal to form familiar multi-sided formations.
Sand and shine:
After cooling, the diamond is sliced and polished, just like nature’s best. The cut, colour, carat, and purity can then get evaluated.