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CVD Diamonds
How do CVD diamonds compare to natural diamonds?
CVD diamonds are a kind of popular lab-grown diamonds.
CVD diamonds share the same crystal structure and chemical composition as natural mined diamonds. So, they are equally sparkling in appearance and as strong as the latter.
The main difference between them lies in the formation process. The former is grown in labs while the latter is naturally formed deep within the earth. Perfect conditions are unavailable for natural diamonds because nature is uncontrollable and filled with bacteria. Therefore, natural diamonds always have to some extent inclusions.
However, CVD diamonds are lab-grown in a controlled environment.
What is a CVD diamond?
Chemical vapor deposition (CVD) is a diamond growth technique from hydrocarbon gas mixtures and has been emerged in recent years. This process begins with a diamond seed crystal in the plasma chamber. Carbon-rich gases are pumped into the chamber and broken down into carbon atoms that become layered onto the seed crystal for rough diamond growth through regulated temperature and pressure.
What differences are there between CVD diamonds and HPHT (High-Pressure High Temperature) diamonds?
The advantages of CVD diamonds are listed below in comparison with HPHT synthetic diamonds:
1）No need for high pressure. CVD technique requires high temperature but not as high as that for the HPHT diamonds.
2）Much bigger CVD diamonds can be created by using a big diamond seed crystal.
3）The growth environment in the vacuum chamber is better conditioned, so the performance of CVD diamonds can be well controlled.
4）HPHT diamonds are hard to be truly colorless because even minimal exposure to nitrogen or boron during the process will give the diamond a subtle yellow or blue hue. On contrary, in-depth research of CVD growth diamonds has been conducted by ZS-Tech to fulfill key industrial breakthroughs with upgraded technologies.
The MPCVD technique can improve diamond quality, yield and accuracy, reduce energy consumption and enhance the functions. This technique makes ZS-Tech one of the few companies that can produce CVD diamonds without the need for color treatment. In 2019, Our CVD diamonds were certified by the International Gemological Institute (IGI) as the world’s only pure CVD diamond kind.
Grading Scales for Lab-grown Diamonds
Just like natural diamonds, lab-grown diamonds are graded and priced by the 4Cs. Despite slightly different types of inclusions and color shades, the most important factor for each lab-growth diamond lies in the finished product. A G color and SI1 clarity CVD diamond are as sparkling as an earth-grown diamond with the same grades in color and clarity (assuming that they’re cut to the same proportions).
Today, many authoritative diamond grading institutes have introduced a new “5Cs + 2T” system to grade CVD lab-created diamonds. The 2T is the acronym for transparency and treatment. ZS-Tech (in CVD diamonds) is one of the few IGI-certified makers of As-grown CVD diamonds.
