CVD vs HPHT Diamonds: Does the Growth Method Matter?

Two processes produce virtually all lab-grown diamonds. Both make genuine diamond — the difference matters to manufacturers more than to buyers.

CVD (chemical vapour deposition)

A diamond seed sits in a chamber filled with carbon-rich plasma; carbon atoms deposit layer by layer onto the seed. CVD is well suited to large, high-clarity stones and is the method behind most 2ct+ goods.

HPHT (high pressure high temperature)

A seed is subjected to extreme heat and pressure, replicating the conditions of the earth's mantle. HPHT grows quickly and is common in smaller sizes.

Can you tell them apart?

Not by eye. A gemologist can identify the growth method with specialised equipment, and the certificate notes it. Optically, both can reach D–F colour and VS clarity or better.

What you should actually judge

Buy the finished stone, not the method: cut quality, colour, clarity, and the certificate. We select on those criteria regardless of how the stone was grown.

Read more in what are lab-grown diamonds.