2.0-2.5 Ct HPHT DEF Colour Diamond Lab Created Diamond Raw Stones

2.0-2.5 ct HPHT DEF color rough diamond lab created diamond raw stones for sale

HPHT VS CVD?

As we know that there are two methods for producing lab grown diamonds, high temperature and high pressure and cvd. Which of these two methods is better for cultivated diamonds?

HPHT Technology: The high temperature and high pressure technology completely simulates the growth process of natural diamonds, reproduces the reaction of the carbon element layer on the ground and converts graphite into diamonds.
HPHT method (temperature 1 400 ℃ -1 700 ℃, pressure 5.2GPa-5.6GPa) Diamond refers to an environment that simulates the growth of natural diamonds, in a hexahedral high-pressure machine, graphite, diamond powder or graphite-diamond powder is used as the carbon source , The equiaxed crystal system formed in the growth environment of high temperature and high pressure, metal catalyst, etc. It only takes a few weeks to produce 20 carats of cultivated diamonds using the high temperature and high pressure method.

The growth process is to put high-purity graphite as a carbon source in the high temperature zone of the growth chamber of the top press, and place diamond seeds in the low temperature zone. Driven by a certain temperature gradient, the carbon source diffuses from the high concentration area at the high temperature to the low concentration area at the low temperature. The diamond seeds in the low temperature area are supersaturated and crystallized, then cooled and taken out, and concentrated nitric acid is used to remove the diamond surface impurities.

CVD Technology:Usually under the action of high temperature plasma, carbon-containing gas is dissociated, and carbon atoms are deposited on the substrate to form a diamond film.Single crystal diamonds are usually formed by the deposition of carbon atoms on the diamond substrate. Carbon-containing gas usually refers to a mixed gas containing nitrogen, methane and hydrogen. Methane is the source of carbon atoms in the synthesis of diamonds. Nitrogen can increase the growth rate, and hydrogen can inhibit the formation of graphite. Usually CVD synthetic diamond is carried out under low pressure and high temperature conditions, the pressure is generally less than one atmosphere, and the temperature is about 1 000 ℃.

From what is said above, we can draw a conclusion:Both technologies have their own advantages. HTHP has higher efficiency and better colors, and CVD has better purity. The production of 1 carat cultivated rough diamond, because high temperature and high pressure (HTHP) is formed by the connection of carbon atoms and carbon atoms, so the growth cycle only takes a few days. Chemical vapor deposition (CVD) is to dissociate and grow carbon-containing gas on the seed wafer, and gradually accumulate and accumulate, which requires a growth cycle of several weeks. Because high temperature and high pressure (HTHP) requires a metal catalyst as a solvent to participate in the reaction, it will have some impact on the purity of the diamond, and the purity of chemical vapor deposition (CVD) is slightly better.

Lab Grown Rough Diamonds Details