You’re probably asking yourself, “What’s the difference between cvd vs hpht?” If so, you’re not alone. There’s a lot of conflicting information about both processes. You’ll hear conflicting information from companies, and even from the media. Let’s find out what makes them different and how they can improve your diamonds. Here’s an overview of both processes:
CVD produces a diamond with a yellowish tint
A CVD diamond is a synthetically created diamond with the same chemical composition as a naturally grown diamond. However, the manufacturing process is less time-consuming and requires less energy. In contrast, diamonds grown by natural methods require thousands of years of intense pressure and temperatures, whereas diamonds produced using CVD technology are produced in a matter of minutes. Another benefit of CVD diamonds is their lower cost, which allows consumers to focus on the qualities they’re most interested in.
The reason why CVD diamonds are brown is due to a defect called vacancy. Because CVD processes produce diamonds in layers, they can produce diamonds with a brown hue. While this tint is not caused by plastic deformation, it can be mitigated by going up a color grade. The NVH 0 defect, for example, is a nominal midcap defect that is highly charge transfer-active. Moreover, the defect gains electrons when the diamond is exposed to UV light or heating.
CVD uses less heat and pressure than HPHT
The CVD process is used to grow diamonds. The diamond seed is placed in a closed chamber, and then hydrogen and methane are introduced. The environment is heated to several hundred degrees Celsius to break the gases into carbon atoms, which build up around the diamond seed. Compared to HPHT, this method is more energy efficient, since CVD machines use less heat. However, despite its advantages, CVD diamonds are usually black or brown, and require HPHT treatment. Unlike HPHT, CVD technology is relatively new, and scientists are only beginning to fully realize the benefits of this method.
One of the benefits of CVD is that it uses much less heat and pressure than HPHT. It uses far less heat and pressure to grow diamonds than HPHT, and is a much more efficient and versatile process. It can be used to grow many types of metals, such as gold and platinum, and is ideal for creating solar cells, silicon, and hybrid devices. The main drawback of CVD is the high cost of its components.
CVD produces a diamond with a uniform color
The process of synthesised diamonds is a very simple one, which uses nitrogen in the growth gas to stimulate the growth of the diamond. The nitrogen in the growth gas remains constant throughout the sample, at a concentration of 10 ppm. A typical CVD sample shows a color of yellow with varying concentrations of nitrogen in the outer and inner layers. By changing the dopant, yellow and blue diamonds can be produced, and these layers can also be layered to create a pink-green diamond.
Another important property of a CVD Vs HPHT diamond is its brown color. This characteristic is due to defects in the crystal. The CVD process generates small voids during its growth. Due to the high temperature, vacancies become mobile and reorganize as disks. As they disassemble, they lose energy. The vacancy color in a diamond is a reflection of the amount of energy trapped in the diamond during the growth process.
CVD produces a diamond with a blue nuance
One of the most common misconceptions about lab-grown diamonds is that they have blue undertones. In fact, the blue hue is usually a result of trace amounts of boron added to the growing chamber during the growth process. It’s extremely difficult to remove this element without the aid of costly equipment and lengthy processes. While the GIA does not list diamonds with a blue nuance, IGI and other gemological institutes list these stones as blue.
Often, the reason for the bluish nuance in HPHT diamonds is because these stones have been treated with boron, which can be quite costly and difficult to remove. The boron-containing substance is introduced to the diamond during the growth phase of HPHT. Since the process is so costly and complex, many retailers actively avoid these diamonds. The measurable amount of boron in CVD stones is considered a Type IIb or “blue nuance.”