HPHT vs. CVD Diamonds

If you're exploring lab grown diamonds, you may come across the terms HPHT and CVD. Both are methods used to grow real diamonds in a laboratory — and both produce stones that are chemically, physically, and optically identical to earth-mined diamonds.

Understanding the difference isn't essential to making a great choice. But if you want to go deeper, this guide explains both methods clearly.

What is HPHT?

HPHT stands for high pressure, high temperature. This method grows diamonds under conditions designed to mimic the intense heat and pressure under which diamonds form naturally within the Earth.

What is CVD?

CVD stands for chemical vapor deposition. In this process, carbon-rich gas is introduced into a chamber, and carbon atoms are deposited onto a diamond seed as the crystal grows layer by layer.

How are they different?

The key difference is the growth environment. HPHT recreates extreme pressure and heat, while CVD grows diamond from gas in a controlled chamber. Both produce real diamonds, but they are not identical in process. For many clients, this distinction is simply part of understanding what they are buying. It does not need to make the decision more complicated — it simply adds clarity.

What about color?

Color can be one of the most meaningful points of difference. Some grown diamonds may show different color tendencies depending on how they were created, and some may receive post-growth treatment to improve appearance. This does not make one method automatically better than the other. It simply makes proper disclosure and grading especially important.

Does this matter to buyers?

Yes, but mostly in the context of transparency. A buyer should know whether a diamond is earth or grown, and in the case of grown diamonds, it is helpful to understand whether it was created by HPHT or CVD when that information is available.

Our point of view

At Amber Arc, we believe technical information should support confidence, not create confusion. When a diamond is presented with honesty and clarity, the choice becomes more personal and more meaningful.

What this means at Amber Arc

Amber Arc carries both HPHT and CVD lab grown diamonds. The growth method used for each stone is identified on the IGI certificate that accompanies qualifying pieces — so you always know exactly what you're buying.

We don't treat one method as superior to the other. What matters to us is the quality of the individual stone — its cut, color, clarity, and the grading behind it — not the method used to grow it.

For all lab grown diamond jewelry above $1,000, the IGI certificate is included at no extra charge within our standard production timeframe.

Frequently asked questions