HPHT versus CVD lab grown diamonds? What are the advantages of each method?
There are two main ways of growing lab grown diamonds. Either you use High Pressure High Temperature (HPHT) method or Chemical Vapour Deposition (CVD) method. This article will answer what the difference is between these methods and why you would select one or the other.
Process of growing HPHT vs CVD Lab grown diamonds
HPHT was the first method discovered and used in the process of growing diamonds. It aims to copy the natural diamond growth process. It involves placing a diamond seed in a carbon medium with a catalyst. Carbon is the building blocks of all diamonds whether earth mined or made in a lab. High temperature and high pressure is then applied like when a diamond grows in earth’s core. This deposits the carbon on the diamond seed and makes it grow.
CVD also begins with a diamond seed. The seed is placed in a chamber containing a hydrocarbon gas mixture usually Methane. Next Hydrogen is inserted into the chamber and super heated into a plasma. This creates the right conditions for the carbon to deposit on the diamond seed. An ionisation process takes place and the diamond seed begins to grow.
Both of these processes seem very similar but the reason why lab grown diamonds became so popular and cheap the last couple of years is entirely due to CVD. CVD allowed for growing diamonds that were almost colourless and at a significant lower price due to the need of less heat and energy usage.
Morphology of CVD vs HPHT Lab grown diamonds
The main telltale factor between the two processes of making a lab grown diamond is the morphology. That means how the diamond grows. The CVD diamond grows in one direction while the HPHT diamond grows in fourteen directions. These growth patterns are the main way that earth mined diamonds can be told apart from lab grown diamonds.
Quality of CVD vs HPHT (what does this mean for you)
HPHT has generally been associated with more yellowish coloured diamonds and still is in many cases. It is a technology that has been around for a longer period of time and there is still a lot of old machinery that creates sub-quality items. The CVD method was the first to create colourless diamonds at a low cost. At present day both methods can create perfect diamonds and there is no difference in the end product (except the morphology).
CVD vs HTHT which one is better?
Without proper optical instruments you will not be able to tell the difference. Therefore most of these differences will not matter to you. However a lab grown diamond is still an expensive investment so make sure to get a proper certificate when buying. Our recommendation is therefore to get a diamond with a certificate from a laboratory such as GIA or IGI.
At TIDAN we only use IGI certified lab grown diamonds
Hope this article was helping you with HPHT versus CVD lab grown diamonds and what the advantages is. TIDAN have great experience and knowledge in making custom-made jewelry and the use of lab grown diamonds. If you have any questions, contact us. If you are looking for guidance and inspiration for creating a wedding ring, click Here.